Mohammedan Calendar Conversion Utility

This calendar conversion utility, which depends on Javascript being enabled, is based on the charts in Staal’s text. The conversions are believed accurate to a day one side or the other. The non-Western dating that appears on J&K covers are either in the Hindu samvat system or in the Mohammedan system. Different transcription systems of varying fidelity and consistency are in use. So for one of the months, prepare to see such variations as zelqa'de, Dhiqada, zu-lqa'de, Zu-lqada, Zulgada, Dhaqadah, zi'l-ka'da, zigoda, ziqa'ad, plus more daunting takes that need a more imaginative font set.

Converting hijra dates H to Western dates W using a linear approximation is analogous to converting Celsius-scale temperatures C to Fahrenheit temperatures F. In both situations there is a relative shift of the origin and a difference in the size of the units. The Moslem system is based on the lunar year, which is about eleven days shorter than the solar year. So we may compare the two relations:

Just as 9/5 is the factor by which the centigrade degree is larger than the Fahrenheit degree, the (approximate) factor 354/365 accomodates the fact of the "short" lunar year by about 11 days. Mohammedan months thus do not maintain a fixed correspondence with Western months or with samvat months as the years go by. It may be amusing to calculate where the respective scales cross: –40°F = –40°C exactly on the temperature scales. On the calendars, W = H = +20,000 AD, give or take a millennium. One rather trusts that none of these systems will be in use at that time.