CFCO helps Muslims fast and celebrate Eid on the correct dates

CFCO’s criterion is the “earliest verifiable visibility of the crescent moon somewhere (in North America)”. Islamic day/date/month begins from a clearly “visible” crescent moon after sunset on day 29 or day 30 of the lunation. The place and time for moon’s earliest visibility is where the Moon is vertically above the Sun at sunset. When their relative azimuth is zero, the apparent altitude of the moon at sunset is 10 degrees, and the time lag between the sunset and the moonset exceeds 35 minutes the crescent moon should become visible if the sky is clear, and the horizon is flat. Actual sighting generally occurs before the Sun reaches an altitude of –5 degrees. If the moon’s elongation at sunset is less than 11 degrees and its altitude is less than 8 degrees one needs a good telescope to locate the dimly lit crescent moon. Higher elongation (12+ degrees) may sometimes compensate for a lower (8+) altitude at sunset. However, the first claims of visibility must be confirmed from places west of it within the visibility parabola. If a moon is not seen consistently then odd claims do not fulfill Shariah requirements of  “Ghalabat-az-Zann” (overwhelming probability) for Ramadan and “Ghalabatal-yaqeen” (near certainty) for Eidain. (For details see “Moon-sighting Facts").