[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Gnu-arch-users] s/GMT/UTC/

From: John Meinel
Subject: Re: [Gnu-arch-users] s/GMT/UTC/
Date: Mon, 06 Sep 2004 21:03:05 -0500
User-agent: Mozilla Thunderbird 0.7 (Windows/20040616)

Andrew Suffield wrote:

On Tue, Sep 07, 2004 at 08:14:29AM +1000, Zenaan Harkness wrote:

UTC is the newer name for GMT (actually, technically I thik they're
slightly different times, but anyway...).

UTC is basically the world trying to deny that timezones originate in
Greenwich by renaming it. Political correctness gone completely insane.

My understanding was it was *Coordinated* Universal Time. Meaning they take more than one atomic clock, average the results, and call that UTC, rather than GMT which is only one clock.

My recommendation is to use UTC rather than GMT. It's more accurately

This is not true. It is differently defined, but no more
accurately. It is also unsupported by unix platforms, and anything
else based on time_t; they really give you GMT and call it UTC
(inexplicably). It's actually off by a few seconds. UTC is not
reliably defined in the future; you cannot say with precision what
time it will be in one million seconds, other than "one million
seconds from now"; there is no definition of how many seconds will be
in a given year until that year occurs.

It's not really the most sensible way to describe time.

Actually, it may not be the most *sensible*, but it is the most *accurate*. Because of leap seconds. Basically, it does not take exactly 365 1/4 days to go around the sun, and I believe the earth doesn't rotate exactly 24 hours. So every so often (very rarely, though), a minute will have 61 seconds instead of 60. See here:

If you read through it, you will see where the need arose. Basically, we have atomic clocks that count one second very regularly, but the earth doesn't rotate, nor revolves around the sun with the same regularity. To make January 1st, 0:01 correspond to the same location around the sun, we have to make adjustments here and there.

I could say we should change time to not be so Earth-centric, but since we all live here for now, we'll probably be okay for at least all of my lifetime.


Attachment: signature.asc
Description: OpenPGP digital signature

reply via email to

[Prev in Thread] Current Thread [Next in Thread]