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OptionOfTyesterday at 6:25 PM2 repliesview on HN

I very much remember coding a function that split the string on their components and then rebuild them to ensure the date was created without time zone.

Sometimes a date is just a date. Your birthday is on a date, it doesn't shift by x hours because you moved to another state.

The old Outlook marked birthdays as all-day events, but stored the value with time-zone, meaning all birthdays of people whose birthday I stored in Belgium were now shifted as I moved to California...


Replies

abustamamyesterday at 7:39 PM

I always found it weird when systems code dates as DateTime strings. There needs to be a different primitive for Date, which is inherently timezone-less, and DateTime, which does require a timezone.

After having a bunch of problems with dealing with Dates coded as DateTime, I've begun coding dates as a Date primitive, and wrote functions for calculation between dates ensuring that timezone never creeps its way into it. If there is ever a DateTime string in a Date column in the database, it's impossible to know what the date was supposed to be unless you know you normalized it at some point on the way up.

Then I found that a lot of DatePicker libraries, despite being in "DATE" picker mode, will still append a local timezone to its value. So I had to write a sanitizer for stripping out the TZ before sending up to the server.

That said, I am pretty excited about Temporal, it'll still make other things easier.

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eszedyesterday at 6:38 PM

I mean... That's kinda how it works? More than once I've halfway forgotten birthdays of friends who live in timezones to my east, and then sent them a message saying "Happy birthday! (It still is where I am, lol)".

I'm not necessarily defending the implementation, just pointing out another way in which time is irreducibly ambiguous and cursed.

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