So many things would be fucked by a TZ change that it very rarely makes sense to consider it.
You’re making a calendar app? Fuck it…some folks are gonna get confused…solved by simply emailing your users and telling them to reschedule shit because there’s kind of a big event going on that everyone knows about and has been planning for for years. Hell in all liklihood this is probably easily solved by simply doing a mass migration of events scheduled before the TZ change.
You’re coding for nuclear weapons? Maybe consider it. But probably not.
That is to say: there are ways to solve problems without resorting to writing the most complicated bullshit code ever seen. Unless of course you work on my team - in which case you’d be right at home.
Yes. Not intentionally of course. But yes.
I don’t see how your way is any more predictable or consistent than using UTC. What even is “local time”? Are you assuming they haven’t changed timezone since they created the data? Say…DST happened, or they drove over a border…?
Storing and manipulating in UTC is the most predictable and consistent because it is universal and unchanging. You only need to worry about “local time” at the point of displaying it.