Dinosaurs Day

Takes place 3 times annually, on the 2nd of the month of August, on the 1st of the month of June and on the 15th of the month of May.

Hashtags:
References:
make-a-smile-today.com/friday-august-2/
holidays-and-observances.com/may-15.html
mazetoons.com/2016/06/01/happy-dinosaur-day-june-1st/