diff --git a/docs/source/contributor-guide/index.md b/docs/source/contributor-guide/index.md
index 20e73c7428..2010335407 100644
--- a/docs/source/contributor-guide/index.md
+++ b/docs/source/contributor-guide/index.md
@@ -34,6 +34,7 @@ Benchmarking Guide <benchmarking>
 Adding a New Operator <adding_a_new_operator>
 Adding a New Expression <adding_a_new_expression>
 Supported Spark Expressions <spark_expressions_support>
+Supported Spark Configurations <spark_configs_support>
 Tracing <tracing>
 Profiling <profiling>
 Comet SQL Tests <sql-file-tests.md>
diff --git a/docs/source/contributor-guide/spark_configs_support.md b/docs/source/contributor-guide/spark_configs_support.md
new file mode 100644
index 0000000000..fe1da3cd23
--- /dev/null
+++ b/docs/source/contributor-guide/spark_configs_support.md
@@ -0,0 +1,112 @@
+<!---
+  Licensed to the Apache Software Foundation (ASF) under one
+  or more contributor license agreements.  See the NOTICE file
+  distributed with this work for additional information
+  regarding copyright ownership.  The ASF licenses this file
+  to you under the Apache License, Version 2.0 (the
+  "License"); you may not use this file except in compliance
+  with the License.  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing,
+  software distributed under the License is distributed on an
+  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+  KIND, either express or implied.  See the License for the
+  specific language governing permissions and limitations
+  under the License.
+-->
+
+# Supported Spark Configurations
+
+This document tracks Spark SQL configurations that affect Comet's behavior. For each
+configuration we record which Comet expressions or operators are influenced, what
+verification has been performed, and any known gaps.
+
+## How to Read This Document
+
+The status column uses these values:
+
+- **Supported** -- Comet runs the affected expressions natively under every value of
+  the config, and produces results matching Spark.
+- **Partial** -- Comet runs natively for some values of the config but falls back to
+  Spark for others, or runs natively but with documented incompatibilities.
+- **Falls back** -- Comet does not run the affected expressions natively under this
+  config and always defers to Spark.
+- **Unaudited** -- the config's interaction with Comet has not yet been verified.
+
+## Audited Configurations
+
+- `spark.sql.legacy.timeParserPolicy`
+  - Default: `EXCEPTION`
+  - Status: Falls back (see notes)
+  - Affected expressions: `date_format`, `from_unixtime`, `unix_timestamp`, `to_unix_timestamp`, `to_timestamp`, `to_timestamp_ntz`, `to_date`, `try_to_timestamp` (Spark 4+)
+  - Spark versions checked: 3.4.3, 3.5.8, 4.0.1
+  - Date: 2026-05-02
+
+## Audit Notes
+
+### `spark.sql.legacy.timeParserPolicy`
+
+**Source.** `SQLConf.LEGACY_TIME_PARSER_POLICY` selects the formatter used by
+`TimestampFormatter` and `DateFormatter`:
+
+- `LEGACY` -- `java.text.SimpleDateFormat` / `FastDateFormat`. Lenient parsing.
+- `CORRECTED` -- `java.time.DateTimeFormatter` via `Iso8601TimestampFormatter`. Strict.
+- `EXCEPTION` (default) -- same parser as `CORRECTED`, plus
+  `DateTimeFormatterHelper.checkParsedDiff` raises `SparkUpgradeException`
+  (`INCONSISTENT_BEHAVIOR_CROSS_VERSION`) when the new parser fails on input that the
+  legacy parser would have accepted. Pattern validation also raises
+  `SparkUpgradeException` when a pattern is recognized only by the legacy formatter
+  (this check applies under both `CORRECTED` and `EXCEPTION`).
+
+**Affected expressions.** Determined by tracing `TimestampFormatterHelper`,
+`TimestampFormatter(...)`, and `DateFormatter(...)` usage in
+`sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/datetimeExpressions.scala`
+across Spark 3.4, 3.5, 4.0, and 4.1. Three expression classes mix in
+`TimestampFormatterHelper`:
+
+- `DateFormatClass` -- `date_format`
+- `FromUnixTime` -- `from_unixtime`
+- `ToTimestamp` (abstract) -- `UnixTimestamp` (`unix_timestamp`),
+  `ToUnixTimestamp` (`to_unix_timestamp`), `GetTimestamp` (used by
+  `ParseToTimestamp` for `to_timestamp` / `to_timestamp_ntz`, `ParseToDate` for
+  `to_date`, and Spark 4's `try_to_timestamp`)
+
+`Cast` between strings and date / timestamp also reads the policy via the default
+formatters but is tested separately by `CometCastSuite` and is out of scope here.
+
+**Comet status.** None of the listed expressions consult `legacyTimeParserPolicy` in
+their Comet serde. The native implementations of `date_format`, `from_unixtime`, and
+`unix_timestamp` use a fixed strftime-style mapping that does not vary with policy;
+the remaining four (`to_unix_timestamp`, `to_timestamp`, `to_date`,
+`try_to_timestamp`) have no native implementation and fall back to Spark. Today this
+works because:
+
+- `date_format` is `Compatible` only for a small whitelist of formats under UTC; the
+  whitelisted formats happen to produce identical output under all three policies.
+- `from_unixtime` is marked `Incompatible` and falls back unless
+  `spark.comet.expression.FromUnixTime.allowIncompatible=true` is set.
+- `unix_timestamp(<timestamp_or_date>)` does not call the formatter at all; the
+  string-input overload falls back.
+
+If a Comet contributor adds native string-format parsing or extends the date_format
+whitelist, this audit should be revisited and the policy must be honored explicitly.
+
+**Test coverage.** `spark/src/test/resources/sql-tests/expressions/datetime/`:
+
+- One ConfigMatrix file per expression covering convergent inputs under
+  `LEGACY,CORRECTED,EXCEPTION` (`*_time_parser_policy.sql`).
+- Per-policy files locking in divergent behavior:
+  - `_legacy.sql` -- lenient inputs (single-digit fields, out-of-range values,
+    trailing characters) and legacy-only pattern tokens (`'aaaa'`).
+  - `_corrected.sql` -- the same inputs return null; legacy-only tokens raise
+    `INCONSISTENT_BEHAVIOR_CROSS_VERSION.DATETIME_PATTERN_RECOGNITION` at formatter
+    creation.
+  - `_exception.sql` -- the same inputs raise
+    `INCONSISTENT_BEHAVIOR_CROSS_VERSION.PARSE_DATETIME_BY_NEW_PARSER` at parse time.
+
+**Findings.** All 42 generated test cases pass on Spark 3.4.3, 3.5.8, and 4.0.1. No
+Comet bugs were uncovered by the audit. The tests use `query spark_answer_only` so
+that result-correctness is enforced regardless of whether Comet runs the expression
+natively or falls back.
diff --git a/spark/src/test/resources/sql-tests/expressions/datetime/date_format_time_parser_policy.sql b/spark/src/test/resources/sql-tests/expressions/datetime/date_format_time_parser_policy.sql
new file mode 100644
index 0000000000..a44dff6114
--- /dev/null
+++ b/spark/src/test/resources/sql-tests/expressions/datetime/date_format_time_parser_policy.sql
@@ -0,0 +1,49 @@
+-- Licensed to the Apache Software Foundation (ASF) under one
+-- or more contributor license agreements.  See the NOTICE file
+-- distributed with this work for additional information
+-- regarding copyright ownership.  The ASF licenses this file
+-- to you under the Apache License, Version 2.0 (the
+-- "License"); you may not use this file except in compliance
+-- with the License.  You may obtain a copy of the License at
+--
+--   http://www.apache.org/licenses/LICENSE-2.0
+--
+-- Unless required by applicable law or agreed to in writing,
+-- software distributed under the License is distributed on an
+-- "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+-- KIND, either express or implied.  See the License for the
+-- specific language governing permissions and limitations
+-- under the License.
+
+-- Convergent date_format() behavior across all three timeParserPolicy values.
+-- Patterns here produce identical output under LEGACY, CORRECTED, and EXCEPTION.
+-- ConfigMatrix: spark.sql.legacy.timeParserPolicy=LEGACY,CORRECTED,EXCEPTION
+-- Config: spark.sql.session.timeZone=UTC
+
+statement
+CREATE TABLE test_date_format_policy(ts timestamp) USING parquet
+
+statement
+INSERT INTO test_date_format_policy VALUES (timestamp('2024-06-15 10:30:45')), (timestamp('1970-01-01 00:00:00')), (NULL)
+
+query spark_answer_only
+SELECT date_format(ts, 'yyyy-MM-dd') FROM test_date_format_policy
+
+query spark_answer_only
+SELECT date_format(ts, 'yyyy-MM-dd HH:mm:ss') FROM test_date_format_policy
+
+query spark_answer_only
+SELECT date_format(ts, 'HH:mm:ss') FROM test_date_format_policy
+
+query spark_answer_only
+SELECT date_format(ts, 'yyyyMMdd') FROM test_date_format_policy
+
+query spark_answer_only
+SELECT date_format(ts, 'yyyyMM') FROM test_date_format_policy
+
+-- literal arguments
+query spark_answer_only
+SELECT date_format(timestamp('2024-06-15 10:30:45'), 'yyyy-MM-dd')
+
+query spark_answer_only
+SELECT date_format(NULL, 'yyyy-MM-dd')
diff --git a/spark/src/test/resources/sql-tests/expressions/datetime/date_format_time_parser_policy_corrected.sql b/spark/src/test/resources/sql-tests/expressions/datetime/date_format_time_parser_policy_corrected.sql
new file mode 100644
index 0000000000..700c571122
--- /dev/null
+++ b/spark/src/test/resources/sql-tests/expressions/datetime/date_format_time_parser_policy_corrected.sql
@@ -0,0 +1,33 @@
+-- Licensed to the Apache Software Foundation (ASF) under one
+-- or more contributor license agreements.  See the NOTICE file
+-- distributed with this work for additional information
+-- regarding copyright ownership.  The ASF licenses this file
+-- to you under the Apache License, Version 2.0 (the
+-- "License"); you may not use this file except in compliance
+-- with the License.  You may obtain a copy of the License at
+--
+--   http://www.apache.org/licenses/LICENSE-2.0
+--
+-- Unless required by applicable law or agreed to in writing,
+-- software distributed under the License is distributed on an
+-- "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+-- KIND, either express or implied.  See the License for the
+-- specific language governing permissions and limitations
+-- under the License.
+
+-- date_format() under CORRECTED timeParserPolicy.
+-- Patterns recognized only by the legacy formatter raise SparkUpgradeException at
+-- formatter creation, even under CORRECTED, because validatePatternString is called
+-- with checkLegacy=true.
+-- Config: spark.sql.legacy.timeParserPolicy=CORRECTED
+-- Config: spark.sql.session.timeZone=UTC
+
+statement
+CREATE TABLE test_date_format_corrected(ts timestamp) USING parquet
+
+statement
+INSERT INTO test_date_format_corrected VALUES (timestamp('2024-06-15 10:30:45'))
+
+-- 4-char am/pm marker: legacy accepts, new rejects, validation throws SparkUpgradeException.
+query expect_error(INCONSISTENT_BEHAVIOR_CROSS_VERSION)
+SELECT date_format(ts, 'yyyy-MM-dd aaaa') FROM test_date_format_corrected
diff --git a/spark/src/test/resources/sql-tests/expressions/datetime/date_format_time_parser_policy_exception.sql b/spark/src/test/resources/sql-tests/expressions/datetime/date_format_time_parser_policy_exception.sql
new file mode 100644
index 0000000000..44398e6774
--- /dev/null
+++ b/spark/src/test/resources/sql-tests/expressions/datetime/date_format_time_parser_policy_exception.sql
@@ -0,0 +1,31 @@
+-- Licensed to the Apache Software Foundation (ASF) under one
+-- or more contributor license agreements.  See the NOTICE file
+-- distributed with this work for additional information
+-- regarding copyright ownership.  The ASF licenses this file
+-- to you under the Apache License, Version 2.0 (the
+-- "License"); you may not use this file except in compliance
+-- with the License.  You may obtain a copy of the License at
+--
+--   http://www.apache.org/licenses/LICENSE-2.0
+--
+-- Unless required by applicable law or agreed to in writing,
+-- software distributed under the License is distributed on an
+-- "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+-- KIND, either express or implied.  See the License for the
+-- specific language governing permissions and limitations
+-- under the License.
+
+-- date_format() under EXCEPTION timeParserPolicy (the default).
+-- Patterns rejected by the new formatter but accepted by legacy raise
+-- SparkUpgradeException at formatter creation.
+-- Config: spark.sql.legacy.timeParserPolicy=EXCEPTION
+-- Config: spark.sql.session.timeZone=UTC
+
+statement
+CREATE TABLE test_date_format_exception(ts timestamp) USING parquet
+
+statement
+INSERT INTO test_date_format_exception VALUES (timestamp('2024-06-15 10:30:45'))
+
+query expect_error(INCONSISTENT_BEHAVIOR_CROSS_VERSION)
+SELECT date_format(ts, 'yyyy-MM-dd aaaa') FROM test_date_format_exception
diff --git a/spark/src/test/resources/sql-tests/expressions/datetime/date_format_time_parser_policy_legacy.sql b/spark/src/test/resources/sql-tests/expressions/datetime/date_format_time_parser_policy_legacy.sql
new file mode 100644
index 0000000000..7a8d4f6496
--- /dev/null
+++ b/spark/src/test/resources/sql-tests/expressions/datetime/date_format_time_parser_policy_legacy.sql
@@ -0,0 +1,31 @@
+-- Licensed to the Apache Software Foundation (ASF) under one
+-- or more contributor license agreements.  See the NOTICE file
+-- distributed with this work for additional information
+-- regarding copyright ownership.  The ASF licenses this file
+-- to you under the Apache License, Version 2.0 (the
+-- "License"); you may not use this file except in compliance
+-- with the License.  You may obtain a copy of the License at
+--
+--   http://www.apache.org/licenses/LICENSE-2.0
+--
+-- Unless required by applicable law or agreed to in writing,
+-- software distributed under the License is distributed on an
+-- "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+-- KIND, either express or implied.  See the License for the
+-- specific language governing permissions and limitations
+-- under the License.
+
+-- date_format() under LEGACY timeParserPolicy.
+-- Legacy SimpleDateFormat accepts patterns that the new java.time formatter rejects.
+-- Config: spark.sql.legacy.timeParserPolicy=LEGACY
+-- Config: spark.sql.session.timeZone=UTC
+
+statement
+CREATE TABLE test_date_format_legacy(ts timestamp) USING parquet
+
+statement
+INSERT INTO test_date_format_legacy VALUES (timestamp('2024-06-15 10:30:45')), (timestamp('1970-01-01 00:00:00')), (NULL)
+
+-- Legacy-only token: 4-char am/pm marker is invalid in the new formatter.
+query spark_answer_only
+SELECT date_format(ts, 'yyyy-MM-dd aaaa') FROM test_date_format_legacy
diff --git a/spark/src/test/resources/sql-tests/expressions/datetime/from_unix_time_time_parser_policy.sql b/spark/src/test/resources/sql-tests/expressions/datetime/from_unix_time_time_parser_policy.sql
new file mode 100644
index 0000000000..f4b58abb24
--- /dev/null
+++ b/spark/src/test/resources/sql-tests/expressions/datetime/from_unix_time_time_parser_policy.sql
@@ -0,0 +1,49 @@
+-- Licensed to the Apache Software Foundation (ASF) under one
+-- or more contributor license agreements.  See the NOTICE file
+-- distributed with this work for additional information
+-- regarding copyright ownership.  The ASF licenses this file
+-- to you under the Apache License, Version 2.0 (the
+-- "License"); you may not use this file except in compliance
+-- with the License.  You may obtain a copy of the License at
+--
+--   http://www.apache.org/licenses/LICENSE-2.0
+--
+-- Unless required by applicable law or agreed to in writing,
+-- software distributed under the License is distributed on an
+-- "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+-- KIND, either express or implied.  See the License for the
+-- specific language governing permissions and limitations
+-- under the License.
+
+-- Convergent from_unixtime() behavior across all three timeParserPolicy values.
+-- Patterns here produce identical output under LEGACY, CORRECTED, and EXCEPTION.
+-- ConfigMatrix: spark.sql.legacy.timeParserPolicy=LEGACY,CORRECTED,EXCEPTION
+-- Config: spark.sql.session.timeZone=UTC
+
+statement
+CREATE TABLE test_from_unix_time_policy(t long) USING parquet
+
+statement
+INSERT INTO test_from_unix_time_policy VALUES (0), (1718451045), (-1), (NULL), (2147483647)
+
+query spark_answer_only
+SELECT from_unixtime(t) FROM test_from_unix_time_policy
+
+query spark_answer_only
+SELECT from_unixtime(t, 'yyyy-MM-dd') FROM test_from_unix_time_policy
+
+query spark_answer_only
+SELECT from_unixtime(t, 'yyyy-MM-dd HH:mm:ss') FROM test_from_unix_time_policy
+
+query spark_answer_only
+SELECT from_unixtime(t, 'HH:mm:ss') FROM test_from_unix_time_policy
+
+-- literal arguments
+query spark_answer_only
+SELECT from_unixtime(0)
+
+query spark_answer_only
+SELECT from_unixtime(1718451045, 'yyyy-MM-dd')
+
+query spark_answer_only
+SELECT from_unixtime(NULL, 'yyyy-MM-dd')
diff --git a/spark/src/test/resources/sql-tests/expressions/datetime/from_unix_time_time_parser_policy_corrected.sql b/spark/src/test/resources/sql-tests/expressions/datetime/from_unix_time_time_parser_policy_corrected.sql
new file mode 100644
index 0000000000..6cbdcf4607
--- /dev/null
+++ b/spark/src/test/resources/sql-tests/expressions/datetime/from_unix_time_time_parser_policy_corrected.sql
@@ -0,0 +1,31 @@
+-- Licensed to the Apache Software Foundation (ASF) under one
+-- or more contributor license agreements.  See the NOTICE file
+-- distributed with this work for additional information
+-- regarding copyright ownership.  The ASF licenses this file
+-- to you under the Apache License, Version 2.0 (the
+-- "License"); you may not use this file except in compliance
+-- with the License.  You may obtain a copy of the License at
+--
+--   http://www.apache.org/licenses/LICENSE-2.0
+--
+-- Unless required by applicable law or agreed to in writing,
+-- software distributed under the License is distributed on an
+-- "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+-- KIND, either express or implied.  See the License for the
+-- specific language governing permissions and limitations
+-- under the License.
+
+-- from_unixtime() under CORRECTED timeParserPolicy.
+-- Patterns recognized only by the legacy formatter raise SparkUpgradeException
+-- at formatter creation, even under CORRECTED.
+-- Config: spark.sql.legacy.timeParserPolicy=CORRECTED
+-- Config: spark.sql.session.timeZone=UTC
+
+statement
+CREATE TABLE test_from_unix_time_corrected(t long) USING parquet
+
+statement
+INSERT INTO test_from_unix_time_corrected VALUES (1718451045)
+
+query expect_error(INCONSISTENT_BEHAVIOR_CROSS_VERSION)
+SELECT from_unixtime(t, 'yyyy-MM-dd aaaa') FROM test_from_unix_time_corrected
diff --git a/spark/src/test/resources/sql-tests/expressions/datetime/from_unix_time_time_parser_policy_exception.sql b/spark/src/test/resources/sql-tests/expressions/datetime/from_unix_time_time_parser_policy_exception.sql
new file mode 100644
index 0000000000..cc3fced087
--- /dev/null
+++ b/spark/src/test/resources/sql-tests/expressions/datetime/from_unix_time_time_parser_policy_exception.sql
@@ -0,0 +1,31 @@
+-- Licensed to the Apache Software Foundation (ASF) under one
+-- or more contributor license agreements.  See the NOTICE file
+-- distributed with this work for additional information
+-- regarding copyright ownership.  The ASF licenses this file
+-- to you under the Apache License, Version 2.0 (the
+-- "License"); you may not use this file except in compliance
+-- with the License.  You may obtain a copy of the License at
+--
+--   http://www.apache.org/licenses/LICENSE-2.0
+--
+-- Unless required by applicable law or agreed to in writing,
+-- software distributed under the License is distributed on an
+-- "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+-- KIND, either express or implied.  See the License for the
+-- specific language governing permissions and limitations
+-- under the License.
+
+-- from_unixtime() under EXCEPTION timeParserPolicy (the default).
+-- Patterns rejected by the new formatter but accepted by legacy raise
+-- SparkUpgradeException at formatter creation.
+-- Config: spark.sql.legacy.timeParserPolicy=EXCEPTION
+-- Config: spark.sql.session.timeZone=UTC
+
+statement
+CREATE TABLE test_from_unix_time_exception(t long) USING parquet
+
+statement
+INSERT INTO test_from_unix_time_exception VALUES (1718451045)
+
+query expect_error(INCONSISTENT_BEHAVIOR_CROSS_VERSION)
+SELECT from_unixtime(t, 'yyyy-MM-dd aaaa') FROM test_from_unix_time_exception
diff --git a/spark/src/test/resources/sql-tests/expressions/datetime/from_unix_time_time_parser_policy_legacy.sql b/spark/src/test/resources/sql-tests/expressions/datetime/from_unix_time_time_parser_policy_legacy.sql
new file mode 100644
index 0000000000..0b2f63cb36
--- /dev/null
+++ b/spark/src/test/resources/sql-tests/expressions/datetime/from_unix_time_time_parser_policy_legacy.sql
@@ -0,0 +1,31 @@
+-- Licensed to the Apache Software Foundation (ASF) under one
+-- or more contributor license agreements.  See the NOTICE file
+-- distributed with this work for additional information
+-- regarding copyright ownership.  The ASF licenses this file
+-- to you under the Apache License, Version 2.0 (the
+-- "License"); you may not use this file except in compliance
+-- with the License.  You may obtain a copy of the License at
+--
+--   http://www.apache.org/licenses/LICENSE-2.0
+--
+-- Unless required by applicable law or agreed to in writing,
+-- software distributed under the License is distributed on an
+-- "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+-- KIND, either express or implied.  See the License for the
+-- specific language governing permissions and limitations
+-- under the License.
+
+-- from_unixtime() under LEGACY timeParserPolicy.
+-- Legacy SimpleDateFormat accepts patterns the new java.time formatter rejects.
+-- Config: spark.sql.legacy.timeParserPolicy=LEGACY
+-- Config: spark.sql.session.timeZone=UTC
+
+statement
+CREATE TABLE test_from_unix_time_legacy(t long) USING parquet
+
+statement
+INSERT INTO test_from_unix_time_legacy VALUES (0), (1718451045), (NULL)
+
+-- Legacy-only token: 4-char am/pm marker formats successfully under LEGACY.
+query spark_answer_only
+SELECT from_unixtime(t, 'yyyy-MM-dd aaaa') FROM test_from_unix_time_legacy
diff --git a/spark/src/test/resources/sql-tests/expressions/datetime/to_date_time_parser_policy.sql b/spark/src/test/resources/sql-tests/expressions/datetime/to_date_time_parser_policy.sql
new file mode 100644
index 0000000000..dc46bbfdda
--- /dev/null
+++ b/spark/src/test/resources/sql-tests/expressions/datetime/to_date_time_parser_policy.sql
@@ -0,0 +1,38 @@
+-- Licensed to the Apache Software Foundation (ASF) under one
+-- or more contributor license agreements.  See the NOTICE file
+-- distributed with this work for additional information
+-- regarding copyright ownership.  The ASF licenses this file
+-- to you under the Apache License, Version 2.0 (the
+-- "License"); you may not use this file except in compliance
+-- with the License.  You may obtain a copy of the License at
+--
+--   http://www.apache.org/licenses/LICENSE-2.0
+--
+-- Unless required by applicable law or agreed to in writing,
+-- software distributed under the License is distributed on an
+-- "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+-- KIND, either express or implied.  See the License for the
+-- specific language governing permissions and limitations
+-- under the License.
+
+-- Convergent to_date(string, format) behavior across all three policies.
+-- ConfigMatrix: spark.sql.legacy.timeParserPolicy=LEGACY,CORRECTED,EXCEPTION
+-- Config: spark.sql.session.timeZone=UTC
+
+statement
+CREATE TABLE test_to_date_policy(s string) USING parquet
+
+statement
+INSERT INTO test_to_date_policy VALUES ('2024-06-15'), ('1970-01-01'), (NULL), ('')
+
+query spark_answer_only
+SELECT to_date(s, 'yyyy-MM-dd') FROM test_to_date_policy
+
+query spark_answer_only
+SELECT to_date(s) FROM test_to_date_policy
+
+query spark_answer_only
+SELECT to_date('2024-06-15', 'yyyy-MM-dd')
+
+query spark_answer_only
+SELECT to_date(NULL, 'yyyy-MM-dd')
diff --git a/spark/src/test/resources/sql-tests/expressions/datetime/to_date_time_parser_policy_corrected.sql b/spark/src/test/resources/sql-tests/expressions/datetime/to_date_time_parser_policy_corrected.sql
new file mode 100644
index 0000000000..b8ea693d2a
--- /dev/null
+++ b/spark/src/test/resources/sql-tests/expressions/datetime/to_date_time_parser_policy_corrected.sql
@@ -0,0 +1,35 @@
+-- Licensed to the Apache Software Foundation (ASF) under one
+-- or more contributor license agreements.  See the NOTICE file
+-- distributed with this work for additional information
+-- regarding copyright ownership.  The ASF licenses this file
+-- to you under the Apache License, Version 2.0 (the
+-- "License"); you may not use this file except in compliance
+-- with the License.  You may obtain a copy of the License at
+--
+--   http://www.apache.org/licenses/LICENSE-2.0
+--
+-- Unless required by applicable law or agreed to in writing,
+-- software distributed under the License is distributed on an
+-- "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+-- KIND, either express or implied.  See the License for the
+-- specific language governing permissions and limitations
+-- under the License.
+
+-- to_date() under CORRECTED timeParserPolicy.
+-- Strict java.time parsing returns null for inputs that legacy would accept.
+-- Config: spark.sql.legacy.timeParserPolicy=CORRECTED
+-- Config: spark.sql.session.timeZone=UTC
+
+statement
+CREATE TABLE test_to_date_strict(s string) USING parquet
+
+statement
+INSERT INTO test_to_date_strict VALUES
+  ('2024-1-1'),
+  ('2024-13-01'),
+  ('2024-02-30'),
+  ('2024-01-01garbage'),
+  ('2024')
+
+query spark_answer_only
+SELECT s, to_date(s, 'yyyy-MM-dd') FROM test_to_date_strict ORDER BY s
diff --git a/spark/src/test/resources/sql-tests/expressions/datetime/to_date_time_parser_policy_exception.sql b/spark/src/test/resources/sql-tests/expressions/datetime/to_date_time_parser_policy_exception.sql
new file mode 100644
index 0000000000..127eb463fa
--- /dev/null
+++ b/spark/src/test/resources/sql-tests/expressions/datetime/to_date_time_parser_policy_exception.sql
@@ -0,0 +1,30 @@
+-- Licensed to the Apache Software Foundation (ASF) under one
+-- or more contributor license agreements.  See the NOTICE file
+-- distributed with this work for additional information
+-- regarding copyright ownership.  The ASF licenses this file
+-- to you under the Apache License, Version 2.0 (the
+-- "License"); you may not use this file except in compliance
+-- with the License.  You may obtain a copy of the License at
+--
+--   http://www.apache.org/licenses/LICENSE-2.0
+--
+-- Unless required by applicable law or agreed to in writing,
+-- software distributed under the License is distributed on an
+-- "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+-- KIND, either express or implied.  See the License for the
+-- specific language governing permissions and limitations
+-- under the License.
+
+-- to_date() under EXCEPTION timeParserPolicy (the default).
+-- Inputs accepted by legacy but rejected by the new parser raise SparkUpgradeException.
+-- Config: spark.sql.legacy.timeParserPolicy=EXCEPTION
+-- Config: spark.sql.session.timeZone=UTC
+
+statement
+CREATE TABLE test_to_date_exception(s string) USING parquet
+
+statement
+INSERT INTO test_to_date_exception VALUES ('2024-1-1')
+
+query expect_error(INCONSISTENT_BEHAVIOR_CROSS_VERSION)
+SELECT to_date(s, 'yyyy-MM-dd') FROM test_to_date_exception
diff --git a/spark/src/test/resources/sql-tests/expressions/datetime/to_date_time_parser_policy_legacy.sql b/spark/src/test/resources/sql-tests/expressions/datetime/to_date_time_parser_policy_legacy.sql
new file mode 100644
index 0000000000..e7493e81c6
--- /dev/null
+++ b/spark/src/test/resources/sql-tests/expressions/datetime/to_date_time_parser_policy_legacy.sql
@@ -0,0 +1,35 @@
+-- Licensed to the Apache Software Foundation (ASF) under one
+-- or more contributor license agreements.  See the NOTICE file
+-- distributed with this work for additional information
+-- regarding copyright ownership.  The ASF licenses this file
+-- to you under the Apache License, Version 2.0 (the
+-- "License"); you may not use this file except in compliance
+-- with the License.  You may obtain a copy of the License at
+--
+--   http://www.apache.org/licenses/LICENSE-2.0
+--
+-- Unless required by applicable law or agreed to in writing,
+-- software distributed under the License is distributed on an
+-- "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+-- KIND, either express or implied.  See the License for the
+-- specific language governing permissions and limitations
+-- under the License.
+
+-- to_date() under LEGACY timeParserPolicy.
+-- Lenient SimpleDateFormat parsing accepts inputs that the new formatter rejects.
+-- Config: spark.sql.legacy.timeParserPolicy=LEGACY
+-- Config: spark.sql.session.timeZone=UTC
+
+statement
+CREATE TABLE test_to_date_lenient(s string) USING parquet
+
+statement
+INSERT INTO test_to_date_lenient VALUES
+  ('2024-1-1'),
+  ('2024-13-01'),
+  ('2024-02-30'),
+  ('2024-01-01garbage'),
+  ('2024')
+
+query spark_answer_only
+SELECT s, to_date(s, 'yyyy-MM-dd') FROM test_to_date_lenient ORDER BY s
diff --git a/spark/src/test/resources/sql-tests/expressions/datetime/to_timestamp_time_parser_policy.sql b/spark/src/test/resources/sql-tests/expressions/datetime/to_timestamp_time_parser_policy.sql
new file mode 100644
index 0000000000..527f4d0d3a
--- /dev/null
+++ b/spark/src/test/resources/sql-tests/expressions/datetime/to_timestamp_time_parser_policy.sql
@@ -0,0 +1,47 @@
+-- Licensed to the Apache Software Foundation (ASF) under one
+-- or more contributor license agreements.  See the NOTICE file
+-- distributed with this work for additional information
+-- regarding copyright ownership.  The ASF licenses this file
+-- to you under the Apache License, Version 2.0 (the
+-- "License"); you may not use this file except in compliance
+-- with the License.  You may obtain a copy of the License at
+--
+--   http://www.apache.org/licenses/LICENSE-2.0
+--
+-- Unless required by applicable law or agreed to in writing,
+-- software distributed under the License is distributed on an
+-- "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+-- KIND, either express or implied.  See the License for the
+-- specific language governing permissions and limitations
+-- under the License.
+
+-- Convergent to_timestamp(string, format) behavior across all three policies.
+-- ConfigMatrix: spark.sql.legacy.timeParserPolicy=LEGACY,CORRECTED,EXCEPTION
+-- Config: spark.sql.session.timeZone=UTC
+
+statement
+CREATE TABLE test_to_ts_policy(s string) USING parquet
+
+statement
+INSERT INTO test_to_ts_policy VALUES ('2024-06-15 10:30:45'), ('1970-01-01 00:00:00'), (NULL), ('')
+
+query spark_answer_only
+SELECT to_timestamp(s, 'yyyy-MM-dd HH:mm:ss') FROM test_to_ts_policy
+
+query spark_answer_only
+SELECT to_timestamp(s) FROM test_to_ts_policy
+
+statement
+CREATE TABLE test_to_ts_date_policy(s string) USING parquet
+
+statement
+INSERT INTO test_to_ts_date_policy VALUES ('2024-06-15'), ('1970-01-01'), (NULL)
+
+query spark_answer_only
+SELECT to_timestamp(s, 'yyyy-MM-dd') FROM test_to_ts_date_policy
+
+query spark_answer_only
+SELECT to_timestamp('2024-06-15', 'yyyy-MM-dd')
+
+query spark_answer_only
+SELECT to_timestamp(NULL, 'yyyy-MM-dd')
diff --git a/spark/src/test/resources/sql-tests/expressions/datetime/to_timestamp_time_parser_policy_corrected.sql b/spark/src/test/resources/sql-tests/expressions/datetime/to_timestamp_time_parser_policy_corrected.sql
new file mode 100644
index 0000000000..bb3da3c1ee
--- /dev/null
+++ b/spark/src/test/resources/sql-tests/expressions/datetime/to_timestamp_time_parser_policy_corrected.sql
@@ -0,0 +1,35 @@
+-- Licensed to the Apache Software Foundation (ASF) under one
+-- or more contributor license agreements.  See the NOTICE file
+-- distributed with this work for additional information
+-- regarding copyright ownership.  The ASF licenses this file
+-- to you under the Apache License, Version 2.0 (the
+-- "License"); you may not use this file except in compliance
+-- with the License.  You may obtain a copy of the License at
+--
+--   http://www.apache.org/licenses/LICENSE-2.0
+--
+-- Unless required by applicable law or agreed to in writing,
+-- software distributed under the License is distributed on an
+-- "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+-- KIND, either express or implied.  See the License for the
+-- specific language governing permissions and limitations
+-- under the License.
+
+-- to_timestamp() under CORRECTED timeParserPolicy.
+-- Strict java.time parsing returns null for inputs that legacy would accept.
+-- Config: spark.sql.legacy.timeParserPolicy=CORRECTED
+-- Config: spark.sql.session.timeZone=UTC
+
+statement
+CREATE TABLE test_to_ts_strict(s string) USING parquet
+
+statement
+INSERT INTO test_to_ts_strict VALUES
+  ('2024-1-1'),
+  ('2024-13-01'),
+  ('2024-02-30'),
+  ('2024-01-01garbage'),
+  ('2024')
+
+query spark_answer_only
+SELECT s, to_timestamp(s, 'yyyy-MM-dd') FROM test_to_ts_strict ORDER BY s
diff --git a/spark/src/test/resources/sql-tests/expressions/datetime/to_timestamp_time_parser_policy_exception.sql b/spark/src/test/resources/sql-tests/expressions/datetime/to_timestamp_time_parser_policy_exception.sql
new file mode 100644
index 0000000000..8280f88078
--- /dev/null
+++ b/spark/src/test/resources/sql-tests/expressions/datetime/to_timestamp_time_parser_policy_exception.sql
@@ -0,0 +1,30 @@
+-- Licensed to the Apache Software Foundation (ASF) under one
+-- or more contributor license agreements.  See the NOTICE file
+-- distributed with this work for additional information
+-- regarding copyright ownership.  The ASF licenses this file
+-- to you under the Apache License, Version 2.0 (the
+-- "License"); you may not use this file except in compliance
+-- with the License.  You may obtain a copy of the License at
+--
+--   http://www.apache.org/licenses/LICENSE-2.0
+--
+-- Unless required by applicable law or agreed to in writing,
+-- software distributed under the License is distributed on an
+-- "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+-- KIND, either express or implied.  See the License for the
+-- specific language governing permissions and limitations
+-- under the License.
+
+-- to_timestamp() under EXCEPTION timeParserPolicy (the default).
+-- Inputs accepted by legacy but rejected by the new parser raise SparkUpgradeException.
+-- Config: spark.sql.legacy.timeParserPolicy=EXCEPTION
+-- Config: spark.sql.session.timeZone=UTC
+
+statement
+CREATE TABLE test_to_ts_exception(s string) USING parquet
+
+statement
+INSERT INTO test_to_ts_exception VALUES ('2024-1-1')
+
+query expect_error(INCONSISTENT_BEHAVIOR_CROSS_VERSION)
+SELECT to_timestamp(s, 'yyyy-MM-dd') FROM test_to_ts_exception
diff --git a/spark/src/test/resources/sql-tests/expressions/datetime/to_timestamp_time_parser_policy_legacy.sql b/spark/src/test/resources/sql-tests/expressions/datetime/to_timestamp_time_parser_policy_legacy.sql
new file mode 100644
index 0000000000..438ae73ebb
--- /dev/null
+++ b/spark/src/test/resources/sql-tests/expressions/datetime/to_timestamp_time_parser_policy_legacy.sql
@@ -0,0 +1,35 @@
+-- Licensed to the Apache Software Foundation (ASF) under one
+-- or more contributor license agreements.  See the NOTICE file
+-- distributed with this work for additional information
+-- regarding copyright ownership.  The ASF licenses this file
+-- to you under the Apache License, Version 2.0 (the
+-- "License"); you may not use this file except in compliance
+-- with the License.  You may obtain a copy of the License at
+--
+--   http://www.apache.org/licenses/LICENSE-2.0
+--
+-- Unless required by applicable law or agreed to in writing,
+-- software distributed under the License is distributed on an
+-- "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+-- KIND, either express or implied.  See the License for the
+-- specific language governing permissions and limitations
+-- under the License.
+
+-- to_timestamp() under LEGACY timeParserPolicy.
+-- Lenient SimpleDateFormat parsing accepts inputs that the new formatter rejects.
+-- Config: spark.sql.legacy.timeParserPolicy=LEGACY
+-- Config: spark.sql.session.timeZone=UTC
+
+statement
+CREATE TABLE test_to_ts_lenient(s string) USING parquet
+
+statement
+INSERT INTO test_to_ts_lenient VALUES
+  ('2024-1-1'),
+  ('2024-13-01'),
+  ('2024-02-30'),
+  ('2024-01-01garbage'),
+  ('2024')
+
+query spark_answer_only
+SELECT s, to_timestamp(s, 'yyyy-MM-dd') FROM test_to_ts_lenient ORDER BY s
diff --git a/spark/src/test/resources/sql-tests/expressions/datetime/to_unix_timestamp_time_parser_policy.sql b/spark/src/test/resources/sql-tests/expressions/datetime/to_unix_timestamp_time_parser_policy.sql
new file mode 100644
index 0000000000..a681d34c9c
--- /dev/null
+++ b/spark/src/test/resources/sql-tests/expressions/datetime/to_unix_timestamp_time_parser_policy.sql
@@ -0,0 +1,47 @@
+-- Licensed to the Apache Software Foundation (ASF) under one
+-- or more contributor license agreements.  See the NOTICE file
+-- distributed with this work for additional information
+-- regarding copyright ownership.  The ASF licenses this file
+-- to you under the Apache License, Version 2.0 (the
+-- "License"); you may not use this file except in compliance
+-- with the License.  You may obtain a copy of the License at
+--
+--   http://www.apache.org/licenses/LICENSE-2.0
+--
+-- Unless required by applicable law or agreed to in writing,
+-- software distributed under the License is distributed on an
+-- "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+-- KIND, either express or implied.  See the License for the
+-- specific language governing permissions and limitations
+-- under the License.
+
+-- Convergent to_unix_timestamp(string, format) behavior across all three policies.
+-- ConfigMatrix: spark.sql.legacy.timeParserPolicy=LEGACY,CORRECTED,EXCEPTION
+-- Config: spark.sql.session.timeZone=UTC
+
+statement
+CREATE TABLE test_to_unix_ts_policy(s string) USING parquet
+
+statement
+INSERT INTO test_to_unix_ts_policy VALUES ('2024-06-15 10:30:45'), ('1970-01-01 00:00:00'), (NULL), ('')
+
+query spark_answer_only
+SELECT to_unix_timestamp(s, 'yyyy-MM-dd HH:mm:ss') FROM test_to_unix_ts_policy
+
+query spark_answer_only
+SELECT to_unix_timestamp(s) FROM test_to_unix_ts_policy
+
+statement
+CREATE TABLE test_to_unix_ts_date_policy(s string) USING parquet
+
+statement
+INSERT INTO test_to_unix_ts_date_policy VALUES ('2024-06-15'), ('1970-01-01'), (NULL)
+
+query spark_answer_only
+SELECT to_unix_timestamp(s, 'yyyy-MM-dd') FROM test_to_unix_ts_date_policy
+
+query spark_answer_only
+SELECT to_unix_timestamp('2024-06-15', 'yyyy-MM-dd')
+
+query spark_answer_only
+SELECT to_unix_timestamp(NULL, 'yyyy-MM-dd')
diff --git a/spark/src/test/resources/sql-tests/expressions/datetime/to_unix_timestamp_time_parser_policy_corrected.sql b/spark/src/test/resources/sql-tests/expressions/datetime/to_unix_timestamp_time_parser_policy_corrected.sql
new file mode 100644
index 0000000000..aa235c712b
--- /dev/null
+++ b/spark/src/test/resources/sql-tests/expressions/datetime/to_unix_timestamp_time_parser_policy_corrected.sql
@@ -0,0 +1,35 @@
+-- Licensed to the Apache Software Foundation (ASF) under one
+-- or more contributor license agreements.  See the NOTICE file
+-- distributed with this work for additional information
+-- regarding copyright ownership.  The ASF licenses this file
+-- to you under the Apache License, Version 2.0 (the
+-- "License"); you may not use this file except in compliance
+-- with the License.  You may obtain a copy of the License at
+--
+--   http://www.apache.org/licenses/LICENSE-2.0
+--
+-- Unless required by applicable law or agreed to in writing,
+-- software distributed under the License is distributed on an
+-- "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+-- KIND, either express or implied.  See the License for the
+-- specific language governing permissions and limitations
+-- under the License.
+
+-- to_unix_timestamp() under CORRECTED timeParserPolicy.
+-- Strict java.time parsing returns null for inputs that legacy would accept.
+-- Config: spark.sql.legacy.timeParserPolicy=CORRECTED
+-- Config: spark.sql.session.timeZone=UTC
+
+statement
+CREATE TABLE test_to_unix_ts_strict(s string) USING parquet
+
+statement
+INSERT INTO test_to_unix_ts_strict VALUES
+  ('2024-1-1'),
+  ('2024-13-01'),
+  ('2024-02-30'),
+  ('2024-01-01garbage'),
+  ('2024')
+
+query spark_answer_only
+SELECT s, to_unix_timestamp(s, 'yyyy-MM-dd') FROM test_to_unix_ts_strict ORDER BY s
diff --git a/spark/src/test/resources/sql-tests/expressions/datetime/to_unix_timestamp_time_parser_policy_exception.sql b/spark/src/test/resources/sql-tests/expressions/datetime/to_unix_timestamp_time_parser_policy_exception.sql
new file mode 100644
index 0000000000..25413bc86d
--- /dev/null
+++ b/spark/src/test/resources/sql-tests/expressions/datetime/to_unix_timestamp_time_parser_policy_exception.sql
@@ -0,0 +1,30 @@
+-- Licensed to the Apache Software Foundation (ASF) under one
+-- or more contributor license agreements.  See the NOTICE file
+-- distributed with this work for additional information
+-- regarding copyright ownership.  The ASF licenses this file
+-- to you under the Apache License, Version 2.0 (the
+-- "License"); you may not use this file except in compliance
+-- with the License.  You may obtain a copy of the License at
+--
+--   http://www.apache.org/licenses/LICENSE-2.0
+--
+-- Unless required by applicable law or agreed to in writing,
+-- software distributed under the License is distributed on an
+-- "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+-- KIND, either express or implied.  See the License for the
+-- specific language governing permissions and limitations
+-- under the License.
+
+-- to_unix_timestamp() under EXCEPTION timeParserPolicy (the default).
+-- Inputs accepted by legacy but rejected by the new parser raise SparkUpgradeException.
+-- Config: spark.sql.legacy.timeParserPolicy=EXCEPTION
+-- Config: spark.sql.session.timeZone=UTC
+
+statement
+CREATE TABLE test_to_unix_ts_exception(s string) USING parquet
+
+statement
+INSERT INTO test_to_unix_ts_exception VALUES ('2024-1-1')
+
+query expect_error(INCONSISTENT_BEHAVIOR_CROSS_VERSION)
+SELECT to_unix_timestamp(s, 'yyyy-MM-dd') FROM test_to_unix_ts_exception
diff --git a/spark/src/test/resources/sql-tests/expressions/datetime/to_unix_timestamp_time_parser_policy_legacy.sql b/spark/src/test/resources/sql-tests/expressions/datetime/to_unix_timestamp_time_parser_policy_legacy.sql
new file mode 100644
index 0000000000..493d9c5b56
--- /dev/null
+++ b/spark/src/test/resources/sql-tests/expressions/datetime/to_unix_timestamp_time_parser_policy_legacy.sql
@@ -0,0 +1,35 @@
+-- Licensed to the Apache Software Foundation (ASF) under one
+-- or more contributor license agreements.  See the NOTICE file
+-- distributed with this work for additional information
+-- regarding copyright ownership.  The ASF licenses this file
+-- to you under the Apache License, Version 2.0 (the
+-- "License"); you may not use this file except in compliance
+-- with the License.  You may obtain a copy of the License at
+--
+--   http://www.apache.org/licenses/LICENSE-2.0
+--
+-- Unless required by applicable law or agreed to in writing,
+-- software distributed under the License is distributed on an
+-- "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+-- KIND, either express or implied.  See the License for the
+-- specific language governing permissions and limitations
+-- under the License.
+
+-- to_unix_timestamp() under LEGACY timeParserPolicy.
+-- Lenient SimpleDateFormat parsing accepts inputs that the new formatter rejects.
+-- Config: spark.sql.legacy.timeParserPolicy=LEGACY
+-- Config: spark.sql.session.timeZone=UTC
+
+statement
+CREATE TABLE test_to_unix_ts_lenient(s string) USING parquet
+
+statement
+INSERT INTO test_to_unix_ts_lenient VALUES
+  ('2024-1-1'),
+  ('2024-13-01'),
+  ('2024-02-30'),
+  ('2024-01-01garbage'),
+  ('2024')
+
+query spark_answer_only
+SELECT s, to_unix_timestamp(s, 'yyyy-MM-dd') FROM test_to_unix_ts_lenient ORDER BY s
diff --git a/spark/src/test/resources/sql-tests/expressions/datetime/try_to_timestamp_time_parser_policy.sql b/spark/src/test/resources/sql-tests/expressions/datetime/try_to_timestamp_time_parser_policy.sql
new file mode 100644
index 0000000000..9c67d0466f
--- /dev/null
+++ b/spark/src/test/resources/sql-tests/expressions/datetime/try_to_timestamp_time_parser_policy.sql
@@ -0,0 +1,48 @@
+-- Licensed to the Apache Software Foundation (ASF) under one
+-- or more contributor license agreements.  See the NOTICE file
+-- distributed with this work for additional information
+-- regarding copyright ownership.  The ASF licenses this file
+-- to you under the Apache License, Version 2.0 (the
+-- "License"); you may not use this file except in compliance
+-- with the License.  You may obtain a copy of the License at
+--
+--   http://www.apache.org/licenses/LICENSE-2.0
+--
+-- Unless required by applicable law or agreed to in writing,
+-- software distributed under the License is distributed on an
+-- "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+-- KIND, either express or implied.  See the License for the
+-- specific language governing permissions and limitations
+-- under the License.
+
+-- Convergent try_to_timestamp(string, format) behavior across all three policies.
+-- MinSparkVersion: 4.0
+-- ConfigMatrix: spark.sql.legacy.timeParserPolicy=LEGACY,CORRECTED,EXCEPTION
+-- Config: spark.sql.session.timeZone=UTC
+
+statement
+CREATE TABLE test_try_to_ts_policy(s string) USING parquet
+
+statement
+INSERT INTO test_try_to_ts_policy VALUES ('2024-06-15 10:30:45'), ('1970-01-01 00:00:00'), (NULL), ('')
+
+query spark_answer_only
+SELECT try_to_timestamp(s, 'yyyy-MM-dd HH:mm:ss') FROM test_try_to_ts_policy
+
+query spark_answer_only
+SELECT try_to_timestamp(s) FROM test_try_to_ts_policy
+
+statement
+CREATE TABLE test_try_to_ts_date_policy(s string) USING parquet
+
+statement
+INSERT INTO test_try_to_ts_date_policy VALUES ('2024-06-15'), ('1970-01-01'), (NULL)
+
+query spark_answer_only
+SELECT try_to_timestamp(s, 'yyyy-MM-dd') FROM test_try_to_ts_date_policy
+
+query spark_answer_only
+SELECT try_to_timestamp('2024-06-15', 'yyyy-MM-dd')
+
+query spark_answer_only
+SELECT try_to_timestamp(NULL, 'yyyy-MM-dd')
diff --git a/spark/src/test/resources/sql-tests/expressions/datetime/try_to_timestamp_time_parser_policy_corrected.sql b/spark/src/test/resources/sql-tests/expressions/datetime/try_to_timestamp_time_parser_policy_corrected.sql
new file mode 100644
index 0000000000..1597bfcd11
--- /dev/null
+++ b/spark/src/test/resources/sql-tests/expressions/datetime/try_to_timestamp_time_parser_policy_corrected.sql
@@ -0,0 +1,36 @@
+-- Licensed to the Apache Software Foundation (ASF) under one
+-- or more contributor license agreements.  See the NOTICE file
+-- distributed with this work for additional information
+-- regarding copyright ownership.  The ASF licenses this file
+-- to you under the Apache License, Version 2.0 (the
+-- "License"); you may not use this file except in compliance
+-- with the License.  You may obtain a copy of the License at
+--
+--   http://www.apache.org/licenses/LICENSE-2.0
+--
+-- Unless required by applicable law or agreed to in writing,
+-- software distributed under the License is distributed on an
+-- "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+-- KIND, either express or implied.  See the License for the
+-- specific language governing permissions and limitations
+-- under the License.
+
+-- try_to_timestamp() under CORRECTED timeParserPolicy.
+-- Strict java.time parsing returns null for inputs that legacy would accept.
+-- MinSparkVersion: 4.0
+-- Config: spark.sql.legacy.timeParserPolicy=CORRECTED
+-- Config: spark.sql.session.timeZone=UTC
+
+statement
+CREATE TABLE test_try_to_ts_strict(s string) USING parquet
+
+statement
+INSERT INTO test_try_to_ts_strict VALUES
+  ('2024-1-1'),
+  ('2024-13-01'),
+  ('2024-02-30'),
+  ('2024-01-01garbage'),
+  ('2024')
+
+query spark_answer_only
+SELECT s, try_to_timestamp(s, 'yyyy-MM-dd') FROM test_try_to_ts_strict ORDER BY s
diff --git a/spark/src/test/resources/sql-tests/expressions/datetime/try_to_timestamp_time_parser_policy_exception.sql b/spark/src/test/resources/sql-tests/expressions/datetime/try_to_timestamp_time_parser_policy_exception.sql
new file mode 100644
index 0000000000..5d1b91432e
--- /dev/null
+++ b/spark/src/test/resources/sql-tests/expressions/datetime/try_to_timestamp_time_parser_policy_exception.sql
@@ -0,0 +1,33 @@
+-- Licensed to the Apache Software Foundation (ASF) under one
+-- or more contributor license agreements.  See the NOTICE file
+-- distributed with this work for additional information
+-- regarding copyright ownership.  The ASF licenses this file
+-- to you under the Apache License, Version 2.0 (the
+-- "License"); you may not use this file except in compliance
+-- with the License.  You may obtain a copy of the License at
+--
+--   http://www.apache.org/licenses/LICENSE-2.0
+--
+-- Unless required by applicable law or agreed to in writing,
+-- software distributed under the License is distributed on an
+-- "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+-- KIND, either express or implied.  See the License for the
+-- specific language governing permissions and limitations
+-- under the License.
+
+-- try_to_timestamp() under EXCEPTION timeParserPolicy (the default).
+-- try_to_timestamp swallows DateTimeException/ParseException, but SparkUpgradeException
+-- raised by checkParsedDiff propagates through the catch -- so the EXCEPTION case still
+-- throws on legacy/new divergent inputs.
+-- MinSparkVersion: 4.0
+-- Config: spark.sql.legacy.timeParserPolicy=EXCEPTION
+-- Config: spark.sql.session.timeZone=UTC
+
+statement
+CREATE TABLE test_try_to_ts_exception(s string) USING parquet
+
+statement
+INSERT INTO test_try_to_ts_exception VALUES ('2024-1-1')
+
+query expect_error(INCONSISTENT_BEHAVIOR_CROSS_VERSION)
+SELECT try_to_timestamp(s, 'yyyy-MM-dd') FROM test_try_to_ts_exception
diff --git a/spark/src/test/resources/sql-tests/expressions/datetime/try_to_timestamp_time_parser_policy_legacy.sql b/spark/src/test/resources/sql-tests/expressions/datetime/try_to_timestamp_time_parser_policy_legacy.sql
new file mode 100644
index 0000000000..a72c8ae0b4
--- /dev/null
+++ b/spark/src/test/resources/sql-tests/expressions/datetime/try_to_timestamp_time_parser_policy_legacy.sql
@@ -0,0 +1,36 @@
+-- Licensed to the Apache Software Foundation (ASF) under one
+-- or more contributor license agreements.  See the NOTICE file
+-- distributed with this work for additional information
+-- regarding copyright ownership.  The ASF licenses this file
+-- to you under the Apache License, Version 2.0 (the
+-- "License"); you may not use this file except in compliance
+-- with the License.  You may obtain a copy of the License at
+--
+--   http://www.apache.org/licenses/LICENSE-2.0
+--
+-- Unless required by applicable law or agreed to in writing,
+-- software distributed under the License is distributed on an
+-- "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+-- KIND, either express or implied.  See the License for the
+-- specific language governing permissions and limitations
+-- under the License.
+
+-- try_to_timestamp() under LEGACY timeParserPolicy.
+-- Lenient SimpleDateFormat parsing accepts inputs that the new formatter rejects.
+-- MinSparkVersion: 4.0
+-- Config: spark.sql.legacy.timeParserPolicy=LEGACY
+-- Config: spark.sql.session.timeZone=UTC
+
+statement
+CREATE TABLE test_try_to_ts_lenient(s string) USING parquet
+
+statement
+INSERT INTO test_try_to_ts_lenient VALUES
+  ('2024-1-1'),
+  ('2024-13-01'),
+  ('2024-02-30'),
+  ('2024-01-01garbage'),
+  ('2024')
+
+query spark_answer_only
+SELECT s, try_to_timestamp(s, 'yyyy-MM-dd') FROM test_try_to_ts_lenient ORDER BY s
diff --git a/spark/src/test/resources/sql-tests/expressions/datetime/unix_timestamp_time_parser_policy.sql b/spark/src/test/resources/sql-tests/expressions/datetime/unix_timestamp_time_parser_policy.sql
new file mode 100644
index 0000000000..25737128e4
--- /dev/null
+++ b/spark/src/test/resources/sql-tests/expressions/datetime/unix_timestamp_time_parser_policy.sql
@@ -0,0 +1,50 @@
+-- Licensed to the Apache Software Foundation (ASF) under one
+-- or more contributor license agreements.  See the NOTICE file
+-- distributed with this work for additional information
+-- regarding copyright ownership.  The ASF licenses this file
+-- to you under the Apache License, Version 2.0 (the
+-- "License"); you may not use this file except in compliance
+-- with the License.  You may obtain a copy of the License at
+--
+--   http://www.apache.org/licenses/LICENSE-2.0
+--
+-- Unless required by applicable law or agreed to in writing,
+-- software distributed under the License is distributed on an
+-- "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+-- KIND, either express or implied.  See the License for the
+-- specific language governing permissions and limitations
+-- under the License.
+
+-- Convergent unix_timestamp(string, format) behavior across all three policies.
+-- Strictly-formatted inputs parse identically under LEGACY, CORRECTED, and EXCEPTION.
+-- ConfigMatrix: spark.sql.legacy.timeParserPolicy=LEGACY,CORRECTED,EXCEPTION
+-- Config: spark.sql.session.timeZone=UTC
+
+statement
+CREATE TABLE test_unix_ts_policy(s string) USING parquet
+
+statement
+INSERT INTO test_unix_ts_policy VALUES ('2024-06-15 10:30:45'), ('1970-01-01 00:00:00'), (NULL), ('')
+
+query spark_answer_only
+SELECT unix_timestamp(s, 'yyyy-MM-dd HH:mm:ss') FROM test_unix_ts_policy
+
+query spark_answer_only
+SELECT unix_timestamp(s) FROM test_unix_ts_policy
+
+-- date-only input with date-only pattern
+statement
+CREATE TABLE test_unix_ts_date_policy(s string) USING parquet
+
+statement
+INSERT INTO test_unix_ts_date_policy VALUES ('2024-06-15'), ('1970-01-01'), (NULL)
+
+query spark_answer_only
+SELECT unix_timestamp(s, 'yyyy-MM-dd') FROM test_unix_ts_date_policy
+
+-- literal arguments
+query spark_answer_only
+SELECT unix_timestamp('2024-06-15', 'yyyy-MM-dd')
+
+query spark_answer_only
+SELECT unix_timestamp(NULL, 'yyyy-MM-dd')
diff --git a/spark/src/test/resources/sql-tests/expressions/datetime/unix_timestamp_time_parser_policy_corrected.sql b/spark/src/test/resources/sql-tests/expressions/datetime/unix_timestamp_time_parser_policy_corrected.sql
new file mode 100644
index 0000000000..71a4c6d380
--- /dev/null
+++ b/spark/src/test/resources/sql-tests/expressions/datetime/unix_timestamp_time_parser_policy_corrected.sql
@@ -0,0 +1,36 @@
+-- Licensed to the Apache Software Foundation (ASF) under one
+-- or more contributor license agreements.  See the NOTICE file
+-- distributed with this work for additional information
+-- regarding copyright ownership.  The ASF licenses this file
+-- to you under the Apache License, Version 2.0 (the
+-- "License"); you may not use this file except in compliance
+-- with the License.  You may obtain a copy of the License at
+--
+--   http://www.apache.org/licenses/LICENSE-2.0
+--
+-- Unless required by applicable law or agreed to in writing,
+-- software distributed under the License is distributed on an
+-- "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+-- KIND, either express or implied.  See the License for the
+-- specific language governing permissions and limitations
+-- under the License.
+
+-- unix_timestamp() under CORRECTED timeParserPolicy.
+-- The new java.time formatter is strict: lenient inputs return null without raising
+-- SparkUpgradeException.
+-- Config: spark.sql.legacy.timeParserPolicy=CORRECTED
+-- Config: spark.sql.session.timeZone=UTC
+
+statement
+CREATE TABLE test_unix_ts_strict(s string) USING parquet
+
+statement
+INSERT INTO test_unix_ts_strict VALUES
+  ('2024-1-1'),
+  ('2024-13-01'),
+  ('2024-02-30'),
+  ('2024-01-01garbage'),
+  ('2024')
+
+query spark_answer_only
+SELECT s, unix_timestamp(s, 'yyyy-MM-dd') FROM test_unix_ts_strict ORDER BY s
diff --git a/spark/src/test/resources/sql-tests/expressions/datetime/unix_timestamp_time_parser_policy_exception.sql b/spark/src/test/resources/sql-tests/expressions/datetime/unix_timestamp_time_parser_policy_exception.sql
new file mode 100644
index 0000000000..7a90b44fe6
--- /dev/null
+++ b/spark/src/test/resources/sql-tests/expressions/datetime/unix_timestamp_time_parser_policy_exception.sql
@@ -0,0 +1,31 @@
+-- Licensed to the Apache Software Foundation (ASF) under one
+-- or more contributor license agreements.  See the NOTICE file
+-- distributed with this work for additional information
+-- regarding copyright ownership.  The ASF licenses this file
+-- to you under the Apache License, Version 2.0 (the
+-- "License"); you may not use this file except in compliance
+-- with the License.  You may obtain a copy of the License at
+--
+--   http://www.apache.org/licenses/LICENSE-2.0
+--
+-- Unless required by applicable law or agreed to in writing,
+-- software distributed under the License is distributed on an
+-- "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+-- KIND, either express or implied.  See the License for the
+-- specific language governing permissions and limitations
+-- under the License.
+
+-- unix_timestamp() under EXCEPTION timeParserPolicy (the default).
+-- New parser fails on lenient inputs; legacy parser would have succeeded;
+-- DateTimeFormatterHelper.checkParsedDiff converts the failure to SparkUpgradeException.
+-- Config: spark.sql.legacy.timeParserPolicy=EXCEPTION
+-- Config: spark.sql.session.timeZone=UTC
+
+statement
+CREATE TABLE test_unix_ts_exception(s string) USING parquet
+
+statement
+INSERT INTO test_unix_ts_exception VALUES ('2024-1-1')
+
+query expect_error(INCONSISTENT_BEHAVIOR_CROSS_VERSION)
+SELECT unix_timestamp(s, 'yyyy-MM-dd') FROM test_unix_ts_exception
diff --git a/spark/src/test/resources/sql-tests/expressions/datetime/unix_timestamp_time_parser_policy_legacy.sql b/spark/src/test/resources/sql-tests/expressions/datetime/unix_timestamp_time_parser_policy_legacy.sql
new file mode 100644
index 0000000000..259a06d1f2
--- /dev/null
+++ b/spark/src/test/resources/sql-tests/expressions/datetime/unix_timestamp_time_parser_policy_legacy.sql
@@ -0,0 +1,36 @@
+-- Licensed to the Apache Software Foundation (ASF) under one
+-- or more contributor license agreements.  See the NOTICE file
+-- distributed with this work for additional information
+-- regarding copyright ownership.  The ASF licenses this file
+-- to you under the Apache License, Version 2.0 (the
+-- "License"); you may not use this file except in compliance
+-- with the License.  You may obtain a copy of the License at
+--
+--   http://www.apache.org/licenses/LICENSE-2.0
+--
+-- Unless required by applicable law or agreed to in writing,
+-- software distributed under the License is distributed on an
+-- "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+-- KIND, either express or implied.  See the License for the
+-- specific language governing permissions and limitations
+-- under the License.
+
+-- unix_timestamp() under LEGACY timeParserPolicy.
+-- SimpleDateFormat is lenient: single-digit fields, out-of-range values, and trailing
+-- characters all parse successfully.
+-- Config: spark.sql.legacy.timeParserPolicy=LEGACY
+-- Config: spark.sql.session.timeZone=UTC
+
+statement
+CREATE TABLE test_unix_ts_lenient(s string) USING parquet
+
+statement
+INSERT INTO test_unix_ts_lenient VALUES
+  ('2024-1-1'),
+  ('2024-13-01'),
+  ('2024-02-30'),
+  ('2024-01-01garbage'),
+  ('2024')
+
+query spark_answer_only
+SELECT s, unix_timestamp(s, 'yyyy-MM-dd') FROM test_unix_ts_lenient ORDER BY s