How it works
The Islamic calendar is based on lunar cycles. The mean year lasts about 11 days less than the Gregorian year, which causes an offset from one year to another.
The year is pretty easy to spot on coins. It is made of 4 Arabic numerals (١٢٣٤٥٦٧٨٩٠) or Western numerals (1234567890).
For instance, the opposite coin reads ١٣٧٨, that is 1378. The Islamic year 1378 began on July 18, 1958 and ended on July 6, 1959.
Note: Dated on Iranian and some Afghan coins display the same way, but use a different calendar.
Learn to read an Islamic dateThe Islamic calendar starts in 622, the day of Hijra, which is the day the Islamic prophet Muhammad quited Mecca and went to Medina. Each year last 12 lunar months, which last 29 or 30 days. This introduces an offset of 11 days on average in comparison with the Gregorian calendar. That's why it's pretty difficult to convert dates from one calendar to the other.
Year readingWriting years is to be proceed the same way as in English. Only the design of numerals changes.
Here is the conversion table: