zlacker

>>asim+(OP)
I was unaware until this year that it was based on when the moon was _sighted_, not just on a conventional lunar calendar. This leads to very short notice public holidays in a couple of countries AIUI.

>>rsynno+Xv1
This leads to issues in e.g. Norilsk where it is polar summer during important Islam dates and you can often not see the moon at all.