[tz] Ambiguous abbreviations for Australian timezones when daylight savings is in affect

[Guy Harris]

On Apr 2, 2013, at 12:39 PM, Clive D.W. Feather <clive at davros.org> wrote:

> Please bear in mind that the "D" means nothing to most people in the
> English-speaking world - "Daylight Saving" is an American construct that is
> both meaningless and not used by the rest of us.

What term is used by the rest of the English-speaking world?  Does the rest of that part of the English-speaking world that adjusts their clocks twice a year turn their clocks forward on or after 21 June or so and turn them backward on or before 21 September or so?  If not, they don't keep "summer time", so presumably they have some other term more accurate than "summer time" and more meaningful than "daylight saving time".