This book highlights the alarming discordance between traditional moon sighting and the modern paradigm. Muslims predominantly favour the most traditional method of sighting the hilal, or new crescent moon, each lunar month by using the naked eye. This is the case despite the facility of hilal visibility maps that would allow them to determine the Islamic lunar calendar for years in advance. Unknown to most Muslims, radical new shifts have been taking place within the moon sighting community. These moon sighting anomalies along with antiquated and irregular moon sighting decisions are having alarming effects. The social and political effects of anomalous moon sighting decisions will have far-reaching consequences if left unaddressed.