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0 pointskoakuma-chan2mo ago0 comments

What you want there is to stop saying "day" and instead say "24 hours." This way the code is correct and you don't need to deal with time weirdness.

0 comments

danbruc2mo ago

No, because if I want something to happen everyday at 12 o'clock, I have to wait for one day, if I wait for 24 hours, I will be off by an hour for half of the year.

koakuma-chanOP1mo ago

Why do you want something to happen everyday at 12 o'clock specifically? If this is truly what you want, sure.

danbruc1mo ago

Lunch break reminder popup?

loloquwowndueo2mo ago

Only if you live in one of the brain dead countries that observe the dst anachronism.

eureka72mo ago

ok, but they still observe it and you still have to deal with it in your code.

our personal convictions don't change that fact.

mklepaczewski2mo ago

You seem to assume that a day always has 24 hours. Common (but not only) non-24h day lengths are: - 23 hours - 25 hours - 24 hours 1 second - 23 hours 59 minutes 59 seconds

You could assume that a day isn't exactly 24 hours, but it's close-ish to 24 hours. Nope, not even close.

And that assumes that we can treat an hour as a precise measure of time (we can't). On some systems, even a second is not a precise measure of time (second smearing).

To make things worse, those are "simple" edge cases.

Time is hard. I'm not sure if I can make any statement about time that is true.

koakuma-chanOP1mo ago

I am saying that you shouldn't use day as a unit of time. You should use second, minute, hour, etc, because these have a constant duration. sleep(86400) should reliably make your thread sleep for at least 24 hours.

mklepaczewski1mo ago

It depends on the context and the system you’re working with. In some systems, an hour may last 3599, 3600 or 3601 seconds (due to the leap second), a minute may be 59,60 or 61 seconds. Even a second is not always a „true” second.

There’s no single time unit that works for all situations.

j / k navigate · click thread line to collapse

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danbruc2mo ago

No, because if I want something to happen everyday at 12 o'clock, I have to wait for one day, if I wait for 24 hours, I will be off by an hour for half of the year.

koakuma-chanOP1mo ago

Why do you want something to happen everyday at 12 o'clock specifically? If this is truly what you want, sure.

danbruc1mo ago

Lunch break reminder popup?

loloquwowndueo2mo ago

Only if you live in one of the brain dead countries that observe the dst anachronism.

eureka72mo ago

ok, but they still observe it and you still have to deal with it in your code.

our personal convictions don't change that fact.

mklepaczewski2mo ago

You seem to assume that a day always has 24 hours. Common (but not only) non-24h day lengths are: - 23 hours - 25 hours - 24 hours 1 second - 23 hours 59 minutes 59 seconds

You could assume that a day isn't exactly 24 hours, but it's close-ish to 24 hours. Nope, not even close.

And that assumes that we can treat an hour as a precise measure of time (we can't). On some systems, even a second is not a precise measure of time (second smearing).

To make things worse, those are "simple" edge cases.

Time is hard. I'm not sure if I can make any statement about time that is true.

koakuma-chanOP1mo ago

mklepaczewski1mo ago

There’s no single time unit that works for all situations.

j / k navigate · click thread line to collapse