At 14:43 +0000 2001-02-15, Clive D.W. Feather wrote:
David Keegel said:
I think common usage outside this group is that a time zone has variable boundaries, and is something like the set of places which *currently* observe the same time (although perhaps US EST and CDT might be considered different time zones).
Change this to say "currently observe the same time and intend to do so for the indefinite future" and you eliminate that problem.
I presume by "the same time" Clive means "the same time as each other" and not necessarily the same UT offset. That would mean that Queensland would have to be considered as a separate time zone from the other mainland Australian eastern states (and territory), and, under the regimen that applied until 1999 and will possibly continue this year, Tasmania as yet another. The Northern Territory and South Australia would also have to be considered as separate from each other. I don't know whether Australians would see it that way in general. They might concede that they are different time zones while they are observing different times, but I doubt they would otherwise. I assume David is thinking of Indiana, most of which is on the same time as the US central zone during "summer", but is still thought of, by many, as being in the eastern time zone. Instead of doing that, and ignoring Clive's amendment, one could think of the time zone boundary as changing twice a year. The difficulty with that, of course, is that, under one interpretation of such a scenario, (most of) Indiana would change time zone twice a year even though its clocks don't change. The alternative (which seems far superior to me and is consistent with labelling time zones with their offset alone) is to think of Indiana as remaining in the same zone, the boundaries of which move east and west around it in an annual cycle. This accords better with what I imagine is the general Australian perception of a time zone. The North American perception is harder to sustain in Australia, where more than half the country in areal terms (but less than half in population terms) does not observe daylight-saving time. The geographically-based designations "Eastern Time" (ET) and "Central Time" (CT), each meaning whatever the time being observed in its respective zone is on the date in question, cannot be made to work in Australia. Even in North America, in order for them to work universally, most of Indiana, and parts of Canada, _would_ have to be thought of as swapping between the two zones twice a year! I am flabbergasted at the resistance there seems to be to the idea of people knowing what their local offset(s) from UTC is/are. In the vast majority of cases such an offset is a one- or two-digit number with a sign, and nowhere is there a need to know more than two of these, in a world of 8-, 9-, and 10-digit phone numbers and post codes, not to mention PINs and (in the US at least) social security numbers! In a place where daylight saving is practised, it is simply a matter of knowing these two simple numbers (like one's floor, house, apartment, and/or room number) and knowing which one applies at the time, which is simply a matter of knowing whether daylight saving is in force or not. Can't we time-zone whizzes (if I may be so bold as to include myself) allow ourselves to have a tiny bit of conscious influence, rather than (or as well as to start with) bending over backwards to accommodate the whims and follies of the powers that be? We are doing the world a significant favor (aren't we?); it doesn't seem too audacious to make it known what would make it easier for us to continue to do so, especially if the general population would also benefit (we think). Should we be deterred just because the resistance seems almost insurmountable? Would it inevitably threaten our perceived impartiality? --Alex _______________ Alex LIVINGSTON IT, Australian Graduate School of Management (AGSM), UNSW SYDNEY NSW 2052 Fax: +61 2 9931-9349 / Phone: +61 2 9931-9264 / Time: UTC + 10 or 11 hours