Encoding or timezone shift: pre-release and first 30 minutes checklists

Stored timestamps or strings are shifted or corrupted after a driver, locale or timezone change.

The pre-release checklist maps each item to a test class from the incident page. The first-30-minutes checklist covers detection, containment, the rollback decision and customer communication.

6 pre-release items · 6 first-30-minutes items · verified 2026-10-22

Pre-release checklist

PR-01Assert in every environment that the application timezone configuration variable is set to a non-NULL value before the serving change goes live. config
PR-02Diff the timezone and locale settings of the new serving layer against the old one and block the release on any difference. config
PR-03Run a timezone-based calculation through each warehouse driver connection type with an account set to a non-default timezone and compare the result to a stored expected value. integration
PR-04Write a timestamped record through the dashboard in a lower environment and confirm the stored value matches the wall clock time in the account timezone. integration
PR-05Add a post-change smoke step that creates a note, reads its timestamp back and fails if the offset differs from the account timezone. synthetic
PR-06Run one synthetic check as an account with a custom timezone, filter a query by date and confirm the returned rows match a stored expected set. synthetic

First 30 minutes

FM-01Compare the timestamps of records written since the deploy with the account timezone and record the exact offset.
FM-02Identify whether the offset comes from the driver session timezone or from the serving layer timezone variable.
FM-03Roll back the change on every connection type that uses the affected driver, not only the one that triggered the alert.
FM-04Query the count of records written between the deploy and the rollback so that the retroactive correction has a fixed scope.
FM-05Apply the timezone correction to the affected records only after the rollback stops new wrong writes.
FM-06Tell affected customers which accounts, which time window and which calculations or notes carry wrong times.

Download the checklist

Pre-release checklist (Markdown)1.5 KB · v1.0.0
First 30 minutes checklist (Markdown)1.0 KB · v1.0.0

Only in this checklist

PR-05 is the only item among 7 published checklists in this group that relies on synthetic monitoring: Add a post-change smoke step that creates a note, reads its timestamp back and fails if the offset differs from the account timezone.

Questions

What should be checked before a release to prevent Encoding or timezone shift?

6 pre-release items, PR-01 to PR-06. PR-01: Assert in every environment that the application timezone configuration variable is set to a non-NULL value before the serving change goes live.

Is there a rollback plan for Encoding or timezone shift?

The first-30-minutes checklist has 6 items. FM-01: Compare the timestamps of records written since the deploy with the account timezone and record the exact offset.

What should a team do in the first 30 minutes after Encoding or timezone shift is detected?

The first-30-minutes checklist has 6 items. FM-01: Compare the timestamps of records written since the deploy with the account timezone and record the exact offset.

Which configuration checks apply to Encoding or timezone shift?

PR-01: Assert in every environment that the application timezone configuration variable is set to a non-NULL value before the serving change goes live. PR-02: Diff the timezone and locale settings of the new serving layer against the old one and block the release on any difference.

Is a Encoding or timezone shift checklist still needed if deployment is automated?

Yes. Automation runs the steps; the checklist names what the tests must cover: configuration and environment tests, integration tests and synthetic monitoring.

Which pipeline stages does the Encoding or timezone shift checklist cover?

The pre-release items map to the pre-deploy and post-deploy stages.