The 12 Months of the Biblical Jewish Calendar

The calendar was a lunar-solar calendar, meaning that the months were based upon the approximately 29½ days that it takes for the moon to orbit the earth, and the years were based upon the approximately 365¼ days that it takes for the earth to orbit the sun. Each month began on a new moon (thus the middle of each month was a full moon) and each year began on the new moon that occurred closest to (sometimes on) the first day of spring (the vernal equinox). Because 12 months came to 354 days, each 12-month lunar year was approximately 11¼ days short of an actual (solar) year. Therefore, a 13^th month, a leap month, called Veadar, or 2^nd Adar, was added about every third year (approximately seven times every nineteen years) to keep the first of Nisan, the beginning of the year, as near as possible to the first day of spring. The Jewish calendar of today is NOT the same as the calendar that was used by the Jews and the people of the Bible.

The names of these months are sometimes known as the “Babylonian names” because they were adopted by the Jews from the Babylonians during their 70-year captivity (605–535 B.C.) in the nation of Babylonia. Only four of the original ancient Hebrew names of the months are known today.