@JLeslie Really? You must know this.
At the end of the summer, we “fall back” by an hour. At the end of the winter, we “spring ahead” by an hour.
But of course, Australia “springs ahead” around the time that we “fall back”, because we’re in different hemispheres. So the amount of time to add or subtract is not constant between our continents all year round.
To make matters worse, we do not even do the time changes on the same dates.