500
Historically, what happened to the Jewish people in Torah times linking the time period between 17th day of Tamuz and Yom Kippur.
What is Moshe broke the 1st tablets on the 17 day of tamuz after seeing the Golden calf. Moshe pleaded for the Jews. On Rosh Chodesh Elul Moshe was told that forgiveness had occured and to prepare to get the 2nd luchos. On Yom Kippur, he came down with the 2nd tablets and the nation was full of Joy and happiness. From then on, this period became one of divine mercy. Hashem's hands are open to those who want to return