May 30, 2019
9:58 a.m.
The Summer Time Ordinance of 1946 was in force from September 1946 until July 1953 when it was replaced by the Summer Time Ordinance 1953. Therefore the fallback transition between 1947 and 1952 were also at 3:30 Standard Time. Also the fallback day in 1947 should be 11-30 according to the HKO website.