Yes, this is all very nice, except the original question was about month names for a specific calendar. Many of the ‘other’ calendars for specific cultures (.Net term for not the primary calendar of the culture) which are typically observed for religious reasons, have different month names. For example, on the Persian calendar the romanised month name for month 9 is Dey, whereas on the Hijri calendar it’s Ramadan. If you use ar-sa, as you suggest, you’ll just get the Arabic month name from the UmAlQura calendar. I know the same is true for Israel too, the primary calendar is Gregorian based with month names that differ from the Hebrew calendar. If I find the answer, I’ll post it here.