[Chemlak]

That might be a possible enhancement, it depends how custom calendars "recognise" the date format (and could be hugely prone to user input error).

It would have to differentiate between, for example, 25 November 1862 CE and 25 November 1862 BCE - most people don't include the era when typing a date, and the software would have to guess which you meant, and then let you change it easily without having to type the date out in full if the software guessed wrong.

And that's not even mentioning something as trivial as the US mm/dd/yyyy versus the more common dd/mm/yyyy format, which just adds to the difficulty of the software recognising what you're typing in and turning it into a date suitable for your currently active calendar.

So this definitely gets a "ooh, yes, please" from me, but I wouldn't pin my hopes on it happening even by the time calendars become available.