Wednesday marks the last day of February, the shortest month in the Gregorian calendar. It doesn’t have to be this way, according to some advocates who propose a calendar where every year is 13 ...

The Islamic calendar is based on cycles of the moon and is used predominantly by Muslims around the world. It helps us ...

Months follow the phases of the moon. The Islamic Calendar is an example of this. Lunisolar calendars track both the sun and the moon. The Chinese calendar is an example of this.

It didn’t work out. France switched back to the Gregorian calendar 12 years later. The Soviet Union tried its hand at a new calendar in 1929. The state shrunk the week to five days in a dual effort to ...

In the Gregorian calendar, no century year can be a leap year unless it is exactly divisible by 400 - so 2000 was a leap year, with an extra day in February, but not 1900.