Jewish Calendar also popularly called as Hebrew Calendar or Christian Calendar, is a lunisolar calendar used today predominantly for Jewish religious observances. It determines the dates for Jewish holidays and the appropriate public reading of Torah portions, yahrzeits (dates to commemorate the death of a relative), and daily Psalm readings, among many ceremonial uses. In Israel, it is used for religious purposes, provides a time frame for agriculture and is an official calendar for civil purposes, although the latter usage has been steadily declining in favor of the Gregorian calendar.
The Jewish day is of no fixed length. There is no clock in the Jewish scheme, so that the local civil clock is used. In Judaism, an hour is defined as 1/12 of the time from sunrise to sunset, so, during the winter, an hour can be much less than 60 minutes, and during the summer, it can be much more than 60 minutes. he weekdays start with Sunday and proceed to Saturday. Names of weekdays are #1 Yom Rishon #2 Yom Sheni #3 Yom Shlishi #4 Yom Revi'i #5 Yom Chamishi #6 Yom Shishi #7 Yom Shabbat