ars_SA and ars_US locales are missing

[yazeed-mohammad]

when I try to call DateFormat('dd, MMMM yyyy').format(DateTime.now()), faced this bug
Invalid argument(s): Invalid locale "ars_SA"

this language is called Najdi Arabic (العربية النجدية)

Which locale is missing?
ars_SA

Which locale have you considered of using instead, but was not sufficient?
nothing