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This isn't true. For example: If a user schedules an event to happen at 15:35 on July 29th 2021 IST, you cannot know with certainty what the equivalent UTC val
by growse 6y ago
This isn't true.
For example: If a user schedules an event to happen at 15:35 on July 29th 2021 IST, you cannot know with certainty what the equivalent UTC value is. You know what it would be assuming the relationship between IST and UTC stays the same between now and next year. If India suddenly decides to implement some sort of DST, or make any other changes to the definition to IST, the UTC value you stored is now wrong.
Timezones are political, but they're also how people organise their lives. The user's local timezone is context that you can't just discard.
- deleted 6y ago[deleted]
- int_19h 6y ago> If India suddenly decides to implement some sort of DST, or make any other changes to the definition to IST, the UTC value you stored is now wrong. It is not wrong. When timezones change, the database that contains that info is updated - but it still retains information about historical rules, precisely so that earlier dates can still be converted reliably. On the other hand, if you use local times, then you are not able to distinguish between pre- and post-clock change, when the same time repeats twice.
- tchaffee 6y agoHow are you going to know to look for changes to IST when all you have is a UTC date?
- deleted 6y ago[deleted]
- growse 6y agoYou're not converting a historic date though, you're converting a future date. And that's an inherently uncertain process. It is literally impossible to know what UTC time 2021-07-29T15:35:00 IST refers to until it happens. The Indian government is free to redefine IST as they wish, and could choose to do that at 15:34:59.