diff --git a/scripts/build-release.mjs b/scripts/build-release.mjs
index cdd21ea..8411531 100644
--- a/scripts/build-release.mjs
+++ b/scripts/build-release.mjs
@@ -10,7 +10,7 @@ const version = packageManifest.version
 const tag = `v${version}`
 const ref = process.env.CODETRUSS_PLUGIN_RELEASE_REF || 'HEAD'
 const dist = join(root, 'dist')
-const commitDate = execFileSync('git', ['show', '-s', '--format=%cI', ref], {
+const commitDate = execFileSync('git', ['show', '-s', '--format=%cI', `${ref}^{commit}`], {
   cwd: root,
   encoding: 'utf8',
 }).trim()
@@ -60,7 +60,11 @@ for (const [target, tree] of packages) {
     `--mtime=${commitDate}`,
     `--output=${output}`,
     `${ref}:${tree}`,
-  ], { cwd: root, stdio: 'inherit' })
+  ], {
+    cwd: root,
+    env: { ...process.env, TZ: 'UTC' },
+    stdio: 'inherit',
+  })
   const digest = createHash('sha256').update(readFileSync(output)).digest('hex')
   writeFileSync(`${output}.sha256`, `${digest}  ${filename}\n`)
 }
diff --git a/scripts/verify-release.mjs b/scripts/verify-release.mjs
index 4b84a91..7234726 100644
--- a/scripts/verify-release.mjs
+++ b/scripts/verify-release.mjs
@@ -9,9 +9,10 @@ import { setTimeout } from 'node:timers/promises'
 const root = join(dirname(fileURLToPath(import.meta.url)), '..')
 const dist = join(root, 'dist')
 
-function buildAndHash() {
+function buildAndHash(timeZone) {
   execFileSync(process.execPath, [join(root, 'scripts/build-release.mjs')], {
     cwd: root,
+    env: { ...process.env, TZ: timeZone },
     stdio: 'inherit',
   })
   return Object.fromEntries(
@@ -22,10 +23,10 @@ function buildAndHash() {
   )
 }
 
-const first = buildAndHash()
+const first = buildAndHash('Pacific/Honolulu')
 await setTimeout(1_100)
-const second = buildAndHash()
-assert.deepEqual(second, first, 'release archives changed across identical builds')
+const second = buildAndHash('Asia/Tokyo')
+assert.deepEqual(second, first, 'release archives changed across timezones')
 assert.equal(Object.keys(first).filter((name) => name.endsWith('.zip')).length, 2)
 assert.equal(Object.keys(first).filter((name) => name.endsWith('.sha256')).length, 2)