Is anyone aware of a date/time representation system that would work universally (including extraterrestrial places)? I just have been curious about this question for long. Sure, we could keep an earth referential on a moon base, but then what about Mars? As a software developer it is already difficult to always get dates/times properly with timezones, now imagine places which does not have 24 hours per day or the sa…
It depends on which layer you're asking about addressing. You can represent anything non-relatavistic on top of the Unix epoch, and it could be handled as simply as using alternate time zones. The big problems come from huge Earth assumptions about interval duration and interval sequencing being violated. A lunar day is 29.5 Earth days. Does the lunar calendar use solar days, and just have absurdly long weeks and yea…
UTC is better, because at least it is aware of leap seconds, but performing any calculation spanning a year's end involves consulting a database of leap seconds. Notably these aren't determined much in advance, so such calculations involving future dates will also involve leap-second errors.
TAI is best (for non-relativistic non-sidereal purposes), as it is not adjusted to account for leap seconds. You can calculate with it without trouble.
(All three of the above are based on the atomic SI second, so despite their differences, their seconds tick synchronously.)