Leap seconds were applied at the end of 1989 and 1990. Leap seconds are added to the clocks at the same moment everywhere in the world, at 00:00 UTC. On the Western hemisphere they are in December and on Eastern hemisphere they are in January.
In most of Europe, DST ended in September, and because September has only 30 days, the extra hour is not significant here.
In America and Britain, DST ended in October, except in Arizona, where it is not in use.
In Australia, DST ended in March, which is autumn there. Japan does not apply DST.
Therefore:
Phoenix | December |
Austin | October |
London | October |
Helsinki | January |
Canberra | March |
Tokyo | January |
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Approvable answers were received from the following persons: