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.
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.
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.
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.
Some countries alter their observance of DST in line with their observance of Ramadan, which means that the time-offset changes aligned with Ramadan.
Ramadan is observed from one visual sighting of a crescent moon to the next.
Cloud conditions may prevent sighting and thereby alter the official start of Ramadan for an individual location, and from time-to-time, the start of a country's change in timezone.
> Some countries alter their observance of DST in line with their observance of Ramadan, which means that the time-offset changes aligned with Ramadan.
Only Morocco does this, I believe, and it's not even clear that that's actually official time at this point. In 2018, Morocco abolished DST, but it seems unclear what that means in practice.
I'd love it if someone from Morocco could weigh in on what the actual situation is on the ground. Do people still change their clocks for Ramadan? Would they be annoyed if a website kept Moroccan users on standard time during Ramadan?
