In India people Celebrate Hanumath Jayanthi during different periods. 

People in Tamil Nadu Celebrate during Marghazhi (Tamil Month) It comes in either December / January (Marghazi Moolam Amavasai Dhinam)

People in Andhra Celebrate during Chithirai (Tamil Month).  It comes in April. (Chitra Pournami) (Maruthiyim Amsam by Sri Smartha Ramadasan)

People in North India Celebrate on Vaikasi Masam (Tamil Month), Krishna Paksham, Dhasami Saturday, Pooratathi Nakshatram (Hanumath Ashtakam)