How does a new islamic month begin in different countries

Actual Sighting judged by Qadi, or Review Panel. (Bangladesh, India, Pakistan, Oman, Morocco)

Moon born & moonset after sunset.(S.Arabia, sometimes deviates for Ramadan, Shawwal, Zul-Hijja)

Follow Saudi Arabia. (Qatar, Kuwait, UAE, Bahrain, Yemen, Turkey)

Moon Born & moon sets at least 5 minutes after sunset. (Egypt)

News from neighbor countries. (New Zealand gets from Australia, and Suriname gets from Guyana)

Follow first Muslim country that announces it. (Europe, Some Carribean Islands)

Criteria, of age, or altitude, or sunset-moonset lag. (Algeria, and Tunisia)

Age > 8 hours, altitude > 2°, elongation > 3°. (Malaysia, Brunei and Indonesia)

Pre-calculated calendar. Bohra, Ismaiili, and Qadiani community in the world.

No specific criterion! Decision varies year by year. (Nigeria)

Actual sighting confirmed by astronomical calculations. (USA, Canada).
Note: Countries in parentheses are examples



--------------------------------------------------------------------------------