As predicted from the crescent visibility map for 19 April 2015, the Rajab 1436 AH hilal was sighted all over the world on the evening of that Sunday. Therefore, 1 Rajab 1436 AH would begin on 20 April 2015.
Below is the map of the crescent moon visibility and the reported photos of the hilal from several places.
Crescent Visibility Map Rajab 1436 AH
Photos of Crescent Moon for Beginning of Rajab 1436 AH