That's easy, if you're Walmart just use the TZ of your corporate HQ

(That's what I heard anyway)

My non-Walmart startup was expanding from California to other regions many years ago, and there was some debate about whether we’d use UTC or America/Los_Angeles globally. I was part of Team Over My Dead Body.

But on which side? :)

There can be only one!

I work for a different company headquartered in the central time zone and we also do this. On some systems.

Google's internal timestamps are in Pacific Time, too.