Section 15PPPPPP. The governor shall annually set apart September 18, the anniversary of the founding of the United States Air Force, in recognition of its distinguished history of service as a projector of American air power in support and defense of the nation, and by the citizens of the commonwealth who so gallantly served, and shall issue a proclamation recommending that the day be observed by the people in the display of the flag and in appropriate public exercises, commemorative of the services and sacrifices of the citizens of the commonwealth who have served and continue to serve in the defense of the United States.