feat: add tip on the time_bucket SQL function

[fusionet24]

What

Adds a short explainer on time_bucket, released 8 September 2026, and a /s/time-bucket short link.

time_bucket(bucketSize, ts [, origin]) returns the start of the fixed-width window a timestamp falls into, aligned to an origin you choose. It fills the gap date_trunc leaves: any window that isn't a calendar unit, and any grid that doesn't start at midnight.

Why this one

Picked from the September 2026 platform release notes over the other candidates because it is the only entry that is both broadly useful and fully demonstrable in a copy-paste statement — no table, no preview enrolment, no DDL, no cleanup. Auto CDF and ABAC DENY policies need provisioned state before an example proves anything; the Lakeflow connectors and model additions need external credentials.

Contents

site/tips/Data Engineering/TimeBucket.qmd — three runnable statements, each with its verified output:

1. 15-minute latency windows. Six API requests grouped by time_bucket, showing the half-open [start, start + bucketSize) boundary: the event at exactly 09:15:00 opens the second window rather than closing the first, so nothing is double counted.
2. The same data re-anchored with origin set to 00:05, moving the grid to :05/:20/:35/:50. The two events either side of 09:15:00 that the default grid split now share a bucket.
3. A fiscal quarter starting 1 February, next to date_trunc('quarter', …) on the same timestamp. Two different quarters from one value — the point being that reporting against the wrong one moves revenue between periods.

Closes with a table for choosing between the two functions, and the behaviour worth planning for: bucketSize and origin are folded at plan time so neither can come from a column, the session time zone moves daily buckets on TIMESTAMP but not TIMESTAMP_NTZ, an origin on the 31st clamps in short months, and a default 7-day grid anchors on Thursdays because the epoch was one — which is why date_trunc remains the right call for weeks.

Notes for review

• Every output block was computed by hand against the documented bucket arithmetic rather than copied from the reference page's examples.
• The page has no executable chunks, so no _freeze artifact is needed.
• Follows the structure and voice of the existing Unity Catalog/Transactions.qmd tip.

🤖 Generated with Claude Code

https://claude.ai/code/session_018nGDkf2tGUxHXMpRbr9GvM

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Generated by Claude Code

[fusionet24]

Heads up on validation: Validate Site and Deploy does not run on open PRs. Its triggers are push to main/feature/*, pull_request on types: [closed], the Sunday schedule, and manual dispatch — so a branch like this one gets no render check until after merge.

I ran it locally instead, with Quarto 1.8.24 (version: release, same as the workflow):

• quarto render on the new page succeeds, and the page lands in the home listing with its title, description, and the Data Engineering / sql / time-series categories.
• Three SQL blocks and the comparison table render as expected; the Watch for links resolve.
• The only warnings are the pre-existing "unable to read listing preview image" ones that every tip in the repo emits, since none set image:.
• No executable chunks, so nothing is added under _freeze.

The diff is the two intended files only — I reverted the site/.quarto/ cache and site/.gitignore churn that rendering produces locally.

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Generated by Claude Code

[Copilot]

🟡 Changes recommended

Clarify the bucketSize foldability requirement in the tutorial.

Once you've addressed the issues Copilot identified, you can request another Copilot review.

Pull request overview

Adds a Databricks SQL time_bucket tutorial with runnable examples and a /s/time-bucket redirect.

Changes:

• Documents fixed-width, origin-aligned bucketing and comparison with date_trunc.
• Adds the /s/time-bucket short-link redirect.

File summaries

File	Summary	Review note
site/tips/Data Engineering/TimeBucket.qmd	New time_bucket tutorial and examples	Nit (2 votes): Clarify that CASE must select between separate calls with literal intervals.
site/staticwebapp.config.json	Adds the short-link redirect	No review comments.

Review details

• Files reviewed: 2/2 changed files
• Comments generated: 1
• Review effort level: Lite

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[Copilot]

🔵 Needs a closer look

The unresolved moderate issue and two nits should be addressed before approval.

Review details

Suppressed comments (3)

site/tips/Data Engineering/TimeBucket.qmd:186

• TIMESTAMP_NTZ has no time zone, so saying it buckets in UTC is misleading: its value and bucket boundaries are independent of spark.sql.session.timeZone, rather than being converted to UTC. Please describe it as session-time-zone independent and reserve the session-time-zone behavior for TIMESTAMP.

**Time zones differ by type.** `TIMESTAMP_NTZ` buckets in UTC. For `TIMESTAMP`, year-month

site/tips/Data Engineering/TimeBucket.qmd:156

• The promised weekly edge case is missing here: time_bucket(INTERVAL '7' DAY, ...) uses epoch-anchored Thursday boundaries, while date_trunc('week', ...) uses Monday. Because the table recommends time_bucket for arbitrary widths, including day widths, omitting this caveat can silently shift weekly reports; please add it before recommending the calendar function.

`time_bucket` with a default origin and a one-unit interval matches `date_trunc` for
seconds, minutes, hours, days, and months. Prefer `date_trunc` there. It reads better, and
it handles weeks, which start on a Monday rather than at the epoch.

site/tips/Data Engineering/TimeBucket.qmd:171

• The FROM events references make these snippets fail when pasted: no events table or CTE is defined, despite the page promising no setup and complete runnable statements. Please add a small VALUES source (to both forms) or label these as schematic examples so the working form can actually be run.

FROM events;

• Files reviewed: 2/2 changed files
• Comments generated: 0 new
• Review effort level: Lite