The date of the Islamic thirty days calendar can be found in a window at the place of the 3 O’clock time indication with Arabic numerals.

The large display of the moon phase is evolving at the 6’O Clock time indication by 30 steps. Five times a year at the end of each month with 29 days only, the date and connected moon phase have to be corrected advancing to 1.

The Hijri or Islamic calendar is a lunar calendar, based on the rotation of the moon around the world. The Gregorian solar calendar is based on the rotation of the earth around the sun.

The Hijri calendar has 5 lunar months of 29 days, numbered 2, 4,6,8 and 10. The twelfth month of the year has 29 days when it is a common year and 30 days when it is an abundant year.

The remaining months have 30 days. The ninth month of this calendar is in the Muslim region the holy month of Ramadan. The Hijri calendar ends and begins at the time of the new moon. Thus the full moon will always be in the middle of the lunar month.

The Islamic calendar which began in 622 AD is still used in many Islamic countries.