18 April 2019 is Hanuman Jayanti Upvaas. Hanuman Jayanti Upvaas or fasting is observed a day before Hanuman Jayanti festival in most of the places.
It falls on Chaitra Shukla Chaturdasi day. Devotees those who perform Hanuman Jayanti vrat and upvas observe fasting from sunrise to sunset.
And some devotees observe partial fasting with some exceptions of eating Sabudana kichidi, fruits, and milk.
Hanuman Jayanti fasting is broken by offering Hanuman Puja in the evening after sunset. It is to note that Hanuman Jayanti falls on Chaitra Purnima, 19 April 2019.