>I did, too. I can't answer about the origin of the Hijri name, ...
After writing the message, it occured to me that it is probably related to the "Hejra" (in Spanish: Hégira) - Muhammad's journey from Mekka to Yathrib (later known as Medina). At least, it sounds similar, so I thought it might be related. And, the Hejra is the starting point of the calendar.
> ...but the article -beyond the potential to actually write an arabic app- got me very interested about knowing some alternative to the things we assume are totally "universal".
If you mean the calendar, I believe that Islamic countries, in general, use the Islamic calendar. I don't know about other calendars that are currently widely used. Other calendars exist (Jewish, Chinese, etc.), but I don't know whether they are still used on a wide-scale, or whether most countries use the Gregorian calendar instead.
The calendar we usually use, called the Gregorian calendar, is named after pope Gregor XIII, who made the calendar reform in the 16th. century.
Hilmar.
Difference in opinions hath cost many millions of lives: for instance, whether flesh be bread, or bread be flesh; whether whistling be a vice or a virtue; whether it be better to kiss a post, or throw it into the fire... (from Gulliver's Travels)