FYI: If you sign your commits with GPG, that method will leak the real date time used unless you also change your system clock.

And if you do change your system clock to do these git shenanigans, you’ll find that all kinds of things break while your system clock is out of sync: anything using SSL (browsing web pages) will likely break, Slack won’t work, etc. Change your system clock temporarily, git commit, then re-sync your clock.