Is there an accepted criterion for crescent sighting?
It is easy to design a criterion based on certain theories or confirmed sightings. But it is hard for that criterion to withstand the test of actual sighting. We have to be the judge and see if the criterion comes out true to the actual sighting month after month, and year after year. In our own community, records go back to 1932. Month after month, circulars detailing predictions have been regularly published, followed by notification of confirmed sightings. Our community has published calendars from different parts of the world, with remarkable accuracy. This includes the planner from the World Federation. With many years of experience, we have fine tuned our criteria of prediction, so that our calculations are borne out by observation time and again. Today our main criterion depends on the Moon’s angular distance from the Sun at sunset (elongation) and the Moon’s altitude (in degrees) above the horizon after sunset. The age of the Moon is recorded as a guideline. Elongation at sunse
