The structure of the Jewish calendar and the allocation of parshiot in both the annual and the triennial Torah reading cycles are described for the lay reader. This 4th edition includes a new material on date conversion between Jewish and Gregorian calendars and vice versa, new material on Rosh Chodesh and on the common year/leap year separation date. The section on Birkat Hachamah and Tal Umatar prayer dates has been expanded. The expanded list of the Jewish to civil calendar dates for Rosh Hashanah and Pesach including year types now covers over 2300 years. There is also a new appendix providing data regarding the time of the occurrence of the molad of Tishrei and the related calendar postponements for nearly 500 years. And there is now an index.