1. No, many countries use different calenders.
2. Well since it's not, I guess this question is irrelevant.
Here is an interesting article about the different calenders the Islamic world has used.
http://en.wikipedia.org/wiki/Islamic_calendar
2. Well since it's not, I guess this question is irrelevant.
Here is an interesting article about the different calenders the Islamic world has used.
http://en.wikipedia.org/wiki/Islamic_calendar