Jewish New Year’s Day, 5771+ years from the creation of the world. This is the most important time in the Jewish year. Rosh Hashanah (literally "Head of Year") is the beginning of ten special days, called the Days of Penitence. This is the time when Jews say sorry to God for all the bad things they have done in the past year.
2014: 24 September (at sundown) - 26
2015: 13 September (at sundown) - 15
2016: 2 October (at sundown) - 4
2017: 20 September (at sundown) - 22
Sweet foods, like apples dipped in honey and honey cake are eaten during Rosh Hashanah. Some families also celebrate with symbolic foods like the head of a fish, pomegranates, and carrots.
The shofar, a Jewish instrument most often made from a ram’s horn is traditionally blown on Rosh HaShanah.
Rosh Hashanah is the only Jewish holiday which lasts for 2 entire days (considered as one very long day), and the reason for this is to emphasize its importance.
Note that in the Jewish calendar, a holiday begins on the sunset of the previous day, so observing Jews will celebrate Rosh HaShanah on the sunset of 8 September.