Islamic Calendar - Convert Hijri To Civil Date or Civil To Hijri Date

Convert Hijri To Civil Date or Civil To Hijri Date

Conversions may be done online (see list of programmes at the bottom of this page), using the Tabular Islamic calendar (see section above) or, most accurately, through the Jewish calendar, which is accurate to one day in 15,186 years. Theoretically, the days of the months correspond in both calendars if the displacements which are a feature of the Jewish system are ignored. The table below gives, for nineteen years, the Muslim month which corresponds to the first Jewish month.

This table may be extended since every nineteen years the Muslim month number increases by seven. When it goes above twelve, subtract twelve and add one to the year AH. From AD412 to AD632 inclusive the month number is 1 and the calculation gives the month correct to a month or so. AD622 corresponds to BH1 and AH1. For earlier years, year BH = (623 or 622) - year AD).

An example calculation: What is the civil date and year AH of the first day of the first month in the year AD20875?

We first find the Muslim month number corresponding to the first month of the Jewish year which begins in AD20874. Dividing 20874 by 19 gives quotient 1098 and remainder 12. Dividing 2026 by 19 gives quotient 106 and remainder 12. The two years are therefore (1098-106)=992x19 years apart. The Muslim month number corresponding to the first Jewish month is therefore (992x7)=6944 higher than in 2026. To convert into years and months divide by twelve - 6944/12=578 years and 8 months. Adding, we get 1447y 10m + 20874y - 2026y + 578y 8m = 20874y 6m. Therefore, the first month of the Jewish year beginning in AD20874 corresponds to the sixth month of the Muslim year AH20874. The worked example in Hebrew calendar#Conversion between Jewish and civil dates shows that the civil date of the first day of this month (ignoring the displacements) is Friday, 14 June. The year AH20875 will therefore begin seven months later, on the first day of the eighth Jewish month, which the worked example shows to be 7 January, AD20875 (again ignoring the displacements). The date given by this method, being calculated, may differ by a day from the actual date, which is determined by observation.

A reading of the section which follows will show that the year AH20875 is wholly contained within the year AD20875, also that in the Gregorian calendar this correspondence will occur one year earlier. The reason for the discrepancy is that the Gregorian year (like the Julian) is slightly too long, so the Gregorian date for a given AH date will be earlier and the Muslim calendar catches up sooner.