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by zoshi 1889 days ago
My guess is it’s because Unix timestamps aren’t calendar date and times. The same number could mean a different date and time depending on which timezone is used.

Given a Unix timestamp, there’s no way to know which date/time the author intended. The browser can only map a Unix timestamp into the user’s timezone, but it wouldn’t know which timezone the document/page refers to.
1 comments
forgotmypw17 1889 days ago
I don't think this is true, because epoch time does not have a timezone, because 0 already corresponds to a certain timezone. Although epoch time isn't exactly "just UTC", as explained in the very interesting StackOverflow question below, it is close enough, and it does not change with the timezone.

https://stackoverflow.com/questions/23062515/do-unix-timesta...

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zoshi 1889 days ago
A timezone can’t be encoded with a Unix time stamp, or a date without a time, or just a time. Unix timestamps ignore leap seconds and treat days as 86400 seconds, so it doesn’t correspond directly to UTC. And they aren’t readable by humans. There are many reasons Unix timestamps aren’t appropriate for encoding a date and time.
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