HilalMap: Crescent Moon Visibility Map

version: 1.0

HilalMap is a crescent moon (hilal) visibility map generator to help determine the beginning of islamic lunar months both globally and locally. This online tool or map guides moon sighting efforts by predicting the visibility of first crescent moon (hilal) from countries around the world. Thus, it can be used to generate islamic calendar based on the first visibility of the crescent moon as directed by Prophet of Islam: Muhammad pbuh. From the map, we can determine on which day the crescent moon will be first visible and from which countries or region. The beginning of the islamic lunar months can then be ascertained easily.

Crescent moon (hilal) visibility map can also be used to gauge the difficulty level of sighting the first crescent in any countries. The map is presented as color-coded regions representing the difficulty or easiness of the crescent moon sighting in given locations:

• • Green region: crescent moon will be easily visible by naked-eyes.
• • Yellow green: may require optical aids to find the moon.
• • Orange region: only visible using optical aids (telescope).
• • Unshaded region: crescent moon invisible, above horizon.
• • Gray region: moon has set when sun sets.
• • Black region: moon has not reach conjunction at sunset.

This service is still in beta version and under development. The algorithmic codes behind this HilalMap tool involve intensive computation. The generation of the crescent visibility map may need about 20 seconds to finish. So, be prepared and be patient.