sentences:  On Canada Day 1 July, the Snowbirds of the Royal Canadian Air Force perform a flyby over Parliament Hill in Ottawa.In 2017, this flypast was extended to 39 aircraft to mark Canada's 150th birthday.The Pakistan Air Force conducts a flypast every year on 23 March to commemorate the Lahore Declaration and the Republic Day of Pakistan which occurred on 23 March 1956.