Rosh Hashanah, the Jewish New Year, falls on the Hebrew calendar dates of 1 and 2 Tishrei.
Here are the coinciding secular dates for the upcoming years:
2008: September 30-October 1
2009: September 19-20
2010: September 9-10
2011: September 29-30
2012: September 17-18
2013: September 5-6
2014: September 25-26
2015: September 14-15
The Jewish calendar date begins at sundown of the night beforehand.
Thus all holiday observances begin the night before the dates listed.
Jewish calendar dates conclude at nightfall.
Rosh Hashanah is followed by Yom Kippur, The Day of Atonement.