The 12 Months of the Year

A year has 365 days divided into 12 months in the modern day Gregorian calendar. Each month has either 28, 30, or 31 days during the common year.

Calendar with 12 months.

A Leap Year with 366 days takes places nearly every 4 years. This is because we add an extra (intercalary) day at the end of February, the Leap Day on 29 February.

From 10 to 12 months

The Gregorian calendar and its predecessor, the Julian calendar both consist of 12 months. The even earlierRoman calendar also had 12 months, however, only 10 of the months had names.