Brian Inglis asked, "Anyone have access to earlier references to Unix time zones or TZ in sources?" I found one; see second paragraph below. Let me start by saying that I'm an old-timer, and was interested in timekeeping and time zones long before the internet. During my time in the US Army (c. 1970), I recall we definitely used positive numbers for the number of hours west of Greenwich. (More often, though, we used letters, as 'R' for New York time.) I found a map in a US Navy World Time Zone Chart published 1940 which shows positive numbers west of Greenwich and negative numbers east. See https://www.ebay.com/itm/254655643832 . I'm sure there are hundreds of naval charts from and before that with the same convention. When the internet was young and I first saw the use of negative numbers for western offsets, I was sure it was a mistake. I still think so. Dave C. Date sent: Fri, 21 Apr 2023 12:10:39 -0600 To: tz@iana.org Organization: Inglis Subject: Re: [tz] Introduce Etc/UTC+x timezones? From: Brian Inglis via tz <tz@iana.org> Send reply to: Brian.Inglis@Shaw.ca
On 2023-04-21 07:32, Benjamin Drung via tz wrote:
If people are aware of timezones, they often know UTC and their offsets (e.g. Europe/Berlin is UTC+2 summer). But they are probably not aware that the Etc/GMT offsets are inverted (e.g. you have to select Etc/GMT-2 for UTC+2). I was not aware of that and other people as well as the bugs in Ubuntu and Debian indicate (see https://launchpad.net/bugs/1325949 and https://bugs.debian.org/540305).
What do you think about the idea of introducing Etc/UTC+x timezones that have the "correct" offset so that people can select fixed offsets more easily? So Etc/GMT-2 would be renamed to Etc/UTC+2 and Etc/GMT-2 would become a symlink to it (same for all other Etc/GMT+x and Etc/GMT-x timezones).
ISO 4031:1978 first defined the representation of local time differentials, commonly referred to as time zones, with -W/+E.
It appears POSIX +W/-E derives from SVID issue 1, published 1985 based on SVR2, possibly in (commercial) AT&T Unix 5 or earlier, supporting GMT and US time zones all positive.
Anyone have access to earlier references to Unix time zones or TZ in sources?
-- Take care. Thanks, Brian Inglis Calgary, Alberta, Canada
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