On 2018-11-17 19:25, Paul Eggert proposed a change to Hong Kong time:
+# Assume the 1904 switch occurred when the time ball was dropped.
1904-10-30T16:00Z probably is a better assumption for the switch in Hong Kong to UT + 08 h; it is a local midnight, and Macao switched at the same instant. The source quoted gives just an ante quem datetime for the switch. It suggests that the time ball regularly was dropped at 01 h local time, and that local time had been advanced by 00:23:18.14 h at some time on or before the ball was dropped on 1904-10-30. The source also treats the switch to UT + 08 h as a different event, the "final step" in the adoption of UT + 08 h in Hong Kong. On would not expect such a wording if the switch had happened at the same time. Michael Deckers.