The festival of Rosh HaShanah (the Head of the New Year) is observed on Tishrei 1, the first day of the Jewish year. It is the anniversary of the creation of Adam and Eve as well as the world.
This year Rosh HaShanah falls on Saturday September 16 and Sunday September 17. Services both days will begin at 10:30 am.
See below for information about Tashlich.