Moon Sighting and Calculation: Determining the Islamic Months in North America
A survey of the classical positions on sighting the crescent, the role of astronomical calculation, and how communities can approach the start of Ramadan and Eid with unity.
- LFP Fatwa Committee
- March 10, 2026
- Worship
- 35 min read
Introduction
Every year, Muslim communities across North America face the question of when Ramadan begins and when Eid falls. Differences between local masajid can be a source of confusion and, at times, tension.
The classical positions
The Prophet, peace be upon him, said, “Fast when you see it and break your fast when you see it” (al-Bukhari and Muslim). The scholars discussed whether a sighting in one locality binds others, and how far that sighting extends.
The role of calculation
Modern astronomy can predict with great accuracy when the crescent is visible. This paper discusses the views of scholars on using calculation to negate a claimed sighting, to establish the month outright, or to support a sighting.
Toward unity
Whatever method a community follows, the paper emphasizes good relations, avoiding disputes, and following the local community’s decision where differences exist.