Proposal to add Japanese/Buddhist calendar date picker

[ntduy26]

Use case

Japanese and Buddhist Calendar picker style support and date format with other calendar type

Proposal

Apple Date Picker: https://developer.apple.com/documentation/uikit/uidatepicker

[gnprice]

A related, broader issue:

• Custom (non gregorian) calendar in showDatePicker  #77531

This one may be easier to implement than the full #77531, though, because both of these calendars are very similar to the Gregorian calendar: they differ only by renumbering the years.

(Well, there are several Buddhist calendars. But I assume the request is for the one that's used as the civil calendar in Thailand, which I believe is the only one widely supported in software.)