Beginning of new Hebrew month of Elul. Elul is the 6th month of the Hebrew year. Corresponds to August or September on the Gregorian calendar.
Rosh Chodesh Elul begins at sundown on Fri, 14 August 2015.
Please see http://www.jewfaq.org/elul.htm to learn more about this time of year
The key subjects are:
Repentance, Atonement, Teshuva.