Only in Australia could we have two identical time-zone abbreviations that mean different things.
Every couple of years or so, I forget about a quirk in the Olsen time-zone data that removes Australian Eastern/Central/Western Daylight time zone, or so I think.
For over 20 years, the battle has raged: is the hour shift that results from daylight savings Australian Daylight Time or Australian Summer Time?
Here's the quote from John Mackin circa 1991 in the Australiasian zone info that still holds sway:
From John Mackin (1991-03-06): We in Australia have never referred to DST as "daylight" time. It is called "summer" time. Now, by a happy coincidence, "summer" and "standard" happen to start with the same letter; hence, the abbreviation does not change ... The legislation does not actually define abbreviations, at least in this state, but the abbreviation is just commonly taken to be the initials of the phrase, and the legislation here uniformly uses the phrase "summer time" and does not use the phrase "daylight time".
And so it has been.
If time zones were referenced with their full name, there wouldn't be an issue, but on *NIX systems, an abbreviation is returned.Currently, the date command returns:
Fri Oct 12 14:52:43 EST 2012
This is correct, but is that abbreviation Eastern Standard Time or Eastern Summer Time? In Sydney, it would be Summer Time, but in Brisbane it is Standard Time. If you were arranging a phone call between those two cities and stated that it would happen at 10am EST, whose EST is it?
To get a more informative answer, use an -R flag to return a date that confirms the RFC 2822 format.Now the output becomes:
To get a date that shows both the time-zone abbreivation and offset from universal time, you can use the following command:
Fri, 12 Oct 2012 14:55:47 +1100
date +%c" "%z
Fri 12 Oct 2012 15:02:03 EST +1100
From this result, we can see that the computer is in an eastern Australian locale that has shifted its time in line with daylight saving.
It's a lot of work, and I think it would be much easier to change the abbreviation to EDT for daylight savings.
Do you agree? Tell us your opinion in the poll below.
And then there is that other question: should we add an A to the front of our time-zone abbreviations to differenciate ourselves from American eastern timezones?