wdr@cstowe.csoft.co.nz (Bill) (02/24/88)
Hi there Netlanders, Time for a little summary of the replies I got about timezones: Now I know all about timezones :-). I have discovered that there is no such thing as GMT time anymore. It has become Universal Time (UT) or Universal Coordinated Time (UCT) depending on who sent the reply. The appropriate references are ANSI Standard X3.51-1975 and ISO 4031, neither of which I have not got hold of (bit difficult out here) so I can't exactly say which of UT or UCT is the `correct' one. It turns out that Unix is backwards with respect to RFC822 (ANSI/ISO etc) time. Mail headers should have +nnnn if the sending site is East of Greenwich. The Unix timezone offset requires the offset to be -nnnn. All I need to do now is to hack about with smail to get it to shove the appropriate stuff on our mail headers, yeeHarr :->. See Y'all Later, and Thanx for the memories. ----- Praise the Employers for they do not know what I say but pay for the resources. ----- Bill D. Ryder ...!uunet!vuwcomp!dsiramd!pnamd!cstowe!wdr Phone 063-65955 (IDD 64) or wdr@csoft.co.nz Commercial Software N.Z. Ltd., PO Box 4030 Palmerston North, Aotearoa (New Zealand if want to use snail mail)
rancke@diku.dk (Hans Rancke-Madsen.) (02/29/88)
In article <418@cstowe.csoft.co.nz> wdr@cstowe.csoft.co.nz (Bill) writes: >I have discovered that there is no such thing as GMT time anymore. Although GMT may not be "official" any more, I maintain that as long as someone uses the expression, and other persons still understand it, then the concept still exists. (Denmark went metric a *loooong* time ago, but you can still buy butter by the pound here). Hans Rancke, University of Copenhagen ..mcvax!diku!rancke --=-=-=-=-=-=-=-=-=-=-=-=-=-=- - I hate it when people call me paranoid. It makes me feel persecuted.
keld@diku.dk (Keld J|rn Simonsen) (02/29/88)
I think the new term for GMT is UTC - Universal Time Coordinated, not UCT. It is going to be incorporated in the new ISO C standard instead of the GMT.
kannan@tut.cis.ohio-state.edu (Kannan Varadhan) (03/02/88)
rancke@diku.dk (Hans Rancke-Madsen.) writes: >In article <418@cstowe.csoft.co.nz> wdr@cstowe.csoft.co.nz (Bill) writes: > >>I have discovered that there is no such thing as GMT time anymore. > >Although GMT may not be "official" any more, I maintain that as >long as someone uses the expression, and other persons still >understand it, then the concept still exists. > Almost all short-wave radio stations (with the notable exception of the BBC ) call it the UTC. I would regard them as the primary users of the term, and there word would lend it the required respectability :-! KANNAN -- email: kannan@ohio-state.arpa | ....!cbosgd!tut!kannan snail: Kannan Varadhan 306, W. Lane Ave., # 15, Columbus, OH 43201 voice: (614) 297-8720
gwyn@brl-smoke.ARPA (Doug Gwyn ) (03/02/88)
In article <3692@diku.dk> keld@diku.dk (Keld J|rn Simonsen) writes: >I think the new term for GMT is UTC - Universal Time Coordinated, >not UCT. UTC is the symbol but Coordinated Universal Time is the English name.
john@ektools.UUCP (John H. Hall) (03/02/88)
Ok, so GMT is now called UTC or "Universal Coordinated Time". As a
pilot, I know that aviation weather reports, flight plans, and a whole
bunch of other such things are reported in "Zulu time", where "Zulu"
is the ICAO phonetic alphabet's letter "Z". Times are written with a
"Z" suffix, as in "0830Z". Zulu time is EST+5 and EDT+4 (Your
timezones may vary. Half an hour earlier in Newfoundland). Is Zulu
time just another expression of UTC?
Another question about UTC. Does it run from 0000 to 2359, or from
0001 to 2400? What is the UTC at midnight (in Greenwich)?
--
John Hall, Supervisor: Software Tools Group, Product Software Engineering
EASTMAN KODAK COMPANY, 901 Elmgrove Rd., Rochester, NY 14650, 716 726-9345
UUCP: {allegra, rutgers}!rochester!kodak!ektools!john
ARPA: kodak!ektools!john@rochester.ARPAleem@jplpro.JPL.NASA.GOV (Lee Mellinger) (03/04/88)
In article <7393@brl-smoke.ARPA> gwyn@brl.arpa (Doug Gwyn (VLD/VMB) <gwyn>) writes: :In article <3692@diku.dk> keld@diku.dk (Keld J|rn Simonsen) writes: :>I think the new term for GMT is UTC - Universal Time Coordinated, :>not UCT. : :UTC is the symbol but Coordinated Universal Time is the English name. The BIH, in english the International Bureau of Time is headquartered in Paris, France more than ten years ago changed the ordinary time standard from GMT to UTC, as well as some of technical specifications as to how it is calculated. There are several time standards, UTC, UT1 and UT2 and others depending on how they are measured. Lee -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- |Lee F. Mellinger Jet Propulsion Laboratory - NASA| |4800 Oak Grove Drive, Pasadena, CA 91109 818/393-0516 FTS 977-0516 | |-------------------------------------------------------------------------| |UUCP: {ames!cit-vax,psivax}!elroy!jpl-devvax!jplpro!leem | |ARPA: jplpro!leem!@cit-vax.ARPA -or- leem@jplpro.JPL.NASA.GOV | -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
fktsun@violet.waterloo.edu (Frankie Kim-Tak Sun) (03/04/88)
In article <1083@ektools.UUCP>, john@ektools.UUCP (John H. Hall) writes: > ..."Z" suffix, as in "0830Z". Zulu time is EST+5 and EDT+4 (Your > timezones may vary. Half an hour earlier in Newfoundland). Is Zulu > time just another expression of UTC? > > Another question about UTC. Does it run from 0000 to 2359, or from > 0001 to 2400? What is the UTC at midnight (in Greenwich)? Yes, Zulu time is the same as UTC(Coordinated Universal Time, rather than Universal Coordinated Time), although I think Zulu time is the term used most often in aviation and the military?, while the other one is more popular among scientific applications. UTC runs from 0000 to 2359. Therefore, using this convention, midnight UTC is denoted as 0000. Frankie Sun fktsun@violet.waterloo.edu
jra@jc3b21.UUCP (Jay R. Ashworth) (03/06/88)
From article <1083@ektools.UUCP>, by john@ektools.UUCP (John H. Hall): > Ok, so GMT is now called UTC or "Universal Coordinated Time". As a > pilot, I know that aviation weather reports, flight plans, and a whole > bunch of other such things are reported in "Zulu time", where "Zulu" > is the ICAO phonetic alphabet's letter "Z". Times are written with a > "Z" suffix, as in "0830Z". Zulu time is EST+5 and EDT+4 (Your > timezones may vary. Half an hour earlier in Newfoundland). Is Zulu > time just another expression of UTC? Yes. > Another question about UTC. Does it run from 0000 to 2359, or from > 0001 to 2400? What is the UTC at midnight (in Greenwich)? Both. 0000=2400, but 0000 is associated with today's UTC date, while 2400 is assoicated with yesterday's. Generally, "Zulu" is a phonetic expression of "Z", the code for this time zone. All the time zones in the world have a one-letter identifier. The one for Grenwich happens to be "Z". Anyone interested in time might want to write to the NBS, Radio Station WWV, as they have several standard publications about the subject. Unfortunately, I don't have Pub. #'s for this stuff, but they might send you a list... National Bureau of Standards radio Station WWV 200 E. County Rd. 58 Ft Collins CO 80302 -- jra, KA1FJX > > -- > John Hall, Supervisor: Software Tools Group, Product Software Engineering > EASTMAN KODAK COMPANY, 901 Elmgrove Rd., Rochester, NY 14650, 716 726-9345 > UUCP: {allegra, rutgers}!rochester!kodak!ektools!john > ARPA: kodak!ektools!john@rochester.ARPA -- Jay R. Ashworth ---+-- The Great Ashworth & ------------+ ...!uunet!codas! 10974 111th St. N. | Petrillo Production Company | !usfvax2!jc3b21!jra Seminole FL 34648 +-- Gonna hafta face it, I'm addicted to news...-+--------- (813) 397-1859 ----+-- Tampa Bay's Smallest Video Production House -+ :-) !$
msb@sq.uucp (Mark Brader) (03/11/88)
> All the time zones in the world have a one-letter > identifier. The one for Greenwich happens to be "Z". This would be a neat trick, since there are about 35 time zones in the world. Even when you exclude the ones that are on half hours and odder amounts, there are still at least 26, because the International Date Line wanders east and west. Does the single-letter system cover all of these? What does it do about daylight saving time, which creates an additional "zone" just west of the line when in effect? Mark Brader "I will be speaking today about work in progress, SoftQuad Inc. instead of completed research; this was not my Toronto intention when I chose the subject of this lecture, utzoo!sq!msb but the fact is I couldn't get my computer programs msb@sq.com working in time." -- D.E. Knuth
dick@slvblc.UUCP (Dick Flanagan) (03/13/88)
In article <1988Mar11.014836.4816@sq.uucp> msb@sq.uucp (Mark Brader) writes: > > All the time zones in the world have a one-letter > > identifier. The one for Greenwich happens to be "Z". > > This would be a neat trick, since there are about 35 time zones in the world. Well, there are really only 25 "official" time zones around the world. Generally one for each hour of the earth's rotation each day. With two exceptions, each is 15 degrees of longitude (or one hour) wide. Each is given a letter designation. 'J' is omitted (I've often wondered who decides such things) and 'Z' straddles the Prime Meridian through Green- wich, England. The two exceptions are the 'M' and 'Y' zones which are only 7-1/2 degrees wide and which are on either side of the International Date Line. Whereas the time difference in both zones is the same--12 hours--one is a positive difference and the other is negative. > Even when you exclude the ones that are on half hours and odder amounts, > there are still at least 26, because the International Date Line wanders > east and west. Does the single-letter system cover all of these? Obviously not (see below). > What does it do about daylight saving time, which creates an additional > "zone" just west of the line when in effect? Daylight saving times, wandering date/time lines, and the like are social phenomena, not physical ones. Dick -- Dick Flanagan, W6OLD GEnie: FLANAGAN UUCP: ...!ucbvax!ucscc!slvblc!dick Voice: +1 408 336 3481 Internet: slvblc!dick@ucscc.UCSC.EDU LORAN: N037 04.7 W122 04.6 USPO: PO Box 155, Ben Lomond, CA 95005
edw@pinot.zehntel.com (Ed Wright) (03/16/88)
In article <7516@tut.cis.ohio-state.edu> kannan@tut.cis.ohio-state.edu (Kannan Varadhan) writes: >rancke@diku.dk (Hans Rancke-Madsen.) writes: >>In article <418@cstowe.csoft.co.nz> wdr@cstowe.csoft.co.nz (Bill) writes: >>>I have discovered that there is no such thing as GMT time anymore. >Almost all short-wave radio stations (with the notable exception of the >BBC ) call it the UTC. I would regard them as the primary users of the >term, and there word would lend it the required respectability :-! for what its worth... most of them if not say "Universal Coordinated Time" UTC? UCT ? its 17:00 somewhere i believe i'll have another beer Ed Wright KA9AHQ >>>>>> ucbvax--\ I used to be disgusted >>>>>>>> sun--->----zehntel !edw>/dev/null :-) Now >>>>>> varian--/ I'm just amused.