💬 Your Product Feedback Has Been Submitted 🎉

Thank you for taking the time to share your insights with us! Your feedback is invaluable as we build a better GitHub experience for all our users.

Here's what you can expect moving forward ⏩

• Your input will be carefully reviewed and cataloged by members of our product teams. 
  • Due to the high volume of submissions, we may not always be able to provide individual responses.
  • Rest assured, your feedback will help chart our course for product improvements.
• Other users may engage with your post, sharing their own perspectives or experiences. 
• GitHub staff may reach out for further clarification or insight. 
  • We may 'Answer' your discussion if there is a current solution, workaround, or roadmap/changelog post related to the feedback.

Where to look to see what's shipping 👀

• Read the Changelog for real-time updates on the latest GitHub features, enhancements, and calls for feedback.
• Explore our Product Roadmap, which details upcoming major releases and initiatives.

What you can do in the meantime 💻

• Upvote and comment on other user feedback Discussions that resonate with you.
• Add more information at any point! Useful details include: use cases, relevant labels, desired outcomes, and any accompanying screenshots.

As a member of the GitHub community, your participation is essential. While we can't promise that every suggestion will be implemented, we want to emphasize that your feedback is instrumental in guiding our decisions and priorities.

Thank you once again for your contribution to making GitHub even better! We're grateful for your ongoing support and collaboration in shaping the future of our platform. ⭐

The evidence presented here is compelling because it appears to isolate three separate timezone sources that are behaving differently:

1. The commit timestamp display (<relative-time>) follows the browser/tz cookie.
2. The commit-list grouping header appears to follow a server-side or account-level timezone.
3. The underlying Git commit object can contain yet another timezone offset.

If that's what's happening, the issue may not actually be with the commit timestamps themselves, but with the service responsible for generating commitGroups[] before the page is rendered.

One additional diagnostic that might help GitHub engineers:

• Check whether the same account sees identical grouping headers when logged in from different browsers, devices, or geographic locations.
• Check whether a newly created account viewing the same repository receives different group boundaries.
• Compare authenticated and unauthenticated views of the same commit list.

If the grouping remains tied to the account regardless of browser timezone and tz cookie, that would strongly suggest the grouping logic is using a persisted account preference rather than the timezone currently used for rendering commit timestamps.

At minimum, the grouping headers and the displayed commit times should be derived from the same timezone source. Even if GitHub chooses account timezone, browser timezone, or repository timezone, consistency between the two views is what users expect.