Therefore readout of years in the Jewish tradition is connected with solar, instead of lunar, cycles. Year solar also is equal the Jewish tradition to 365 days - to a time interval in which the ground makes a full revolution around of the sun. There is a difference in 11 days between lunar year - total of days in all Jewish months (354 days) - and solar. To liquidate this difference and to bring the Jewish calendar into accord both with lunar, and with solar cycles, the system of usual and leap years has been entered. Usual Jewish year will consist of 12 months: Nissan, Iyar, Sivan, Tammuz, Av, Elul, Tishri, Cheshvan, Kislev, Tevet, Shevat, Adar.
Time in some years add 13-th month which "destroys" a difference between the lunar and solar calendar, collected for some years. Such year name leap. In it two Adar (Adar 1-st and Adar 2-nd). The full cycle of years is equal the Jewish calendar to 19 years. In a nineteen-year annual cycle there are twelve "simple" and seven leap-years. The order of following of simple and leap years is always identical.
Thus, the Jewish calendar - лунно-solar. It differs from the European calendar based only on a solar cycle, therefore each date of a лунно-solar Jewish calendar in different years falls at different numbers of the European calendar, but always on the same season.