Historical information
In the Jewish calendar the month began with the new moon and lasted 29 or 30 days.
Names of months
Originally, no names were used for the months (Genesis 7:11). Until the Babylonian captivity they used the Canaanite names and towards the end of the reign they used numbers (1st, 2nd...).
During the Hellenistic period the Macedonian names (Dystros, Xanthios) began to be used. In the time of Jesus, Roman names were established, from which the current names of the Greek calendar are derived.
The months and their duration - The Importance of the Embolism Month
A Jewish month always begins with the new moon. According to the orbit of the moon, a month may consist of 29 or 30 days.
The calendar contains 12 months, but in leap years an extra month is added, resulting in a total of 13 months in a year. This extra month is a second Adar and is added to maintain the alignment of religious holidays with the seasons. This ensures that Passover will always fall in the spring.
