Tens of thousands gathered to begin reciting Selichos on Motzei Shabbos at Chatzos at shuls throughout Eretz Yisrael and at the Kosel.
Sephardim begin reciting Selichos at the start of Chodesh Elul in order to recite the special tefillos for a period of 40 days prior to Yom Kippur, the same period of time that Moshe Rabbeinu was on Har Sinai.
Ashkenazim begin reciting Selichos on the Motzei Shabbos (or Sunday morning) before Rosh Hashanah, but if there are less than four days between the beginning of Selichos and Rosh Hashana, then the recital begins on the previous Motzei Shabbos.