Adar is the sixth month of the civil year and the twelfth month of the Hebrew calendar. Adar is special because in leap years it is actually two months. Adar Rishon (First Adar) or Adar I which is 30 days and Adar Sheni (Second Adar) or Adar II which has 29 days in it. On years without an additional Adar the month has 29 days in it.
Holidays During The Month:
Fast of the Esther — 13 Adar (11 Adar when the 13th falls on Shabbat)
Purim — 14 Adar
Shushan Purim — 15 Adar
Special Shabbat During The Month: