Comment Re:I absolutely do not get why this is an issue... (Score 1) 103
The entire problem is basically lazy programmers who want to pretend unix time is utc and let someone else deal with the problems*. It isn't. Changing to leap minutes actually makes this problem worse because it is even easier to ignore. Also the it being too easy to ignore is genuinely getting worse even with leap seconds. The idea was that there would be a leap second around once every 1-3 years, so everyone would deal with them regularly and it would be no big deal. But the Earth's rotation unexpectedly stopped slowing down, and then in 2020, started speeding up. (see this plot where the jumps are leap seconds) So there was no leap second between 1999 and 2006 and there hasn't been one since 2017 and there is unlikely to be one soon. There is actually discussion of whether we will need a negative leap second. That is in the spec, but has never been used and is almost never implemented because nobody thought it could happen. So the whole discussion of a leap minute is either essential or almost irrelevant because a negative leap second would break everything but we may not need one for 15 years or more.
* The problem being that the number of SI seconds between unix time of noon Jan 1 2020 (1577880000) and noon Jan 1 2010 (1262347200) is not (1577880000 - 1262347200) = 315532800, it is 315532803 SI seconds (including three leap seconds). i.e. you cannot subtract unix times to get a long time interval. Just like you can't subtract year*365+dayofyear to get the number of days between two dates. Unix time is not the number of SI seconds since 1970, it is the number of (utc) days since 1970 times 24*60*60. Exactly when those ticks happened on any given day is not well defined in the spec and different implementers have made different decisions (some repeat the last second of the day, some stretch the second for some amount of time before and/or after the leap second, sometimes the issue is ignored and the clock was just reset at some arbitrary time). Even the man page for "date" is misleading because the author was too lazy to sort this out and explain it. The simple fact is that a unix second and an SI second are not the same thing and the unix second is not even a uniform measure of time.