alt Hacker NewsWhy not? It sounds like it would be correct even if the employee has a shift that includes a offset change.
Future timestamps should be local because local timezone changes literally change the instant the event it will happen (relative to UTC). For past things, this can’t happen
Correct according to what? An employee who punched in at 9AM wouldn't show up as having punched in at 9AM anymore. Not unless you also store the exact timezone the UTC timestamps have been created with - but that's basically local timestamps with extra steps.