Rabi al-Awwal 1, 1437 will be Sunday, December 13, 2015. There were no sighting reports on Friday, December 11, 2015 (Safar 29, 1437). As such, Safar will complete its cycle of 30 days and Rabi al-Awwal begins at Maghrib on Saturday, December 12, 2015. The 1st of Rabi al-Awwal will be Sunday, December 13, 2015.
