Rosh Hashanah

Rosh Hashanah (“head of the year”) is the Jewish New Year. It takes place in September or October in the Gregorian calendar.  The festival begins at nightfall on the previous day.

In 2014 Rosh Hashanah begins at sundown on Wednesday 24 September and ends at sundown on 26 September.

http://judaism.about.com/od/holidays/a/roshhashanah.htm

Yom Kippur, the day of atonement, is observed ten days later – on Saturday 4 October.