The internet is telling me that Taiwan uses both calendars. Is that not true? Surely even your grandparents know that it's 2023 in the rest of the world.
It's irrelevant to my point though. Just because the standard is used by 99% of people instead of 100% doesn't mean programmers should invent a new one, for the same reason they chose January 1st 1970 and not November 15th 1970 or any other day of the year. There's only one obvious choice.
That list includes things like the "British Regnal year" and its mostly historical calendars that aren't used at all... The real items on it are almost all ceremonial calendars and everyone (who isn't a priest) uses the Gregorian calendar, or at least most people know it. It's the obvious choice for the standard, I'm not sure why people are pretending it's not.
Notably, the newest entry on that list is "Unix time". Just because there's already more than one entry on the list doesn't mean a small group of people should add another. That's not even "there are now 14 standards" that's just deliberately adding to the pile.
> The real items on it are almost all ceremonial calendars and everyone (who isn't a priest) uses the Gregorian calendar, or at least most people know it.
Isn’t this just the “no true scotsman” defense, but for calendars?
No, since year 1 being 2023 solar years ago is a Christian thing, humanity does not agree on this. Among others, Japan, Korea, China as well as a whole host of Muslim countries do not.
I would say it's a secular international standard of Christian origin, similar to how "information" is an English word even if it's actually a French word. The origin of concepts is important but usage is what ultimately defines them, not etymology. The exceptions prove the rule and most of those countries only use the other calendar ceremonially, and the ones that don't are still familiar with the Gregorian calendar.
Regardless, just because the standard is not used by 100% of humanity doesn't justify programmers coming up with their own calendar instead of using the obvious choice. It's unnecessary.