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| author | Andy Parkins <andyparkins@gmail.com> | 2007-01-26 08:58:48 +0000 |
|---|---|---|
| committer | Junio C Hamano <junkio@cox.net> | 2007-01-28 14:35:50 -0800 |
| commit | a69aba6af3e96f8021c194691a851e78febd70bf (patch) | |
| tree | 765ec3a9bd3936cfeff42af19bf780d0e2e252ba | |
| parent | 5558e55c06a1e897f3064f0c8a343d5c9858f6b2 (diff) | |
| download | git-a69aba6af3e96f8021c194691a851e78febd70bf.tar.gz git-a69aba6af3e96f8021c194691a851e78febd70bf.tar.xz | |
UNIX reference time of 1970-01-01 00:00 is UTC timezone, not local time zone
I got bitten because in the UK (where one would expect 1970-01-01 00:00
to be UTC 0) some politicians decided to mess around with daylight
savings time from 1968 to 1971; it was permanently BST (+0100). That
means that on my computer the following is true:
$ date --date="1970-01-01 00:00" +"%F %T %z (%Z)"
1970-01-01 00:00:00 +0100 (BST)
This of course means that the --date argument to date is specified in
local time, not UTC. So when the hooks--update script does this:
date=$(date --date="1970-01-01 00:00:00 $ts seconds")
It's actually saying (in my timezone) "1970-01-01 01:00:00 UTC" + $ts.
Clearly this is wrong. The UNIX epoch started at midnight UTC not 1am
UTC.
This leads to the tagged time in hooks--update being shown as one hour
earlier than the true tagged time (in my timezone). The problem would
be worse for other timezones. For a +1300 timezone on 1970-01-01, the
tagged time would be 13 hours earlier. Oops.
The solution is to force the reference time to UTC, which is what this
patch does. In my timezone:
$ date --date="1970-01-01 00:00 +0000" +"%F %T %z (%Z)"
1970-01-01 01:00:00 +0100 (BST)
Much better.
Signed-off-by: Andy Parkins <andyparkins@gmail.com>
| -rw-r--r-- | templates/hooks--update | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/templates/hooks--update b/templates/hooks--update index 9863a800c..81f706fb0 100644 --- a/templates/hooks--update +++ b/templates/hooks--update @@ -46,7 +46,7 @@ then if [ "$ref_type" = tag ]; then eval $(git cat-file tag $3 | \ sed -n '4s/tagger \([^>]*>\)[^0-9]*\([0-9]*\).*/tagger="\1" ts="\2"/p') - date=$(date --date="1970-01-01 00:00:00 $ts seconds" +"$date_format") + date=$(date --date="1970-01-01 00:00:00 +0000 $ts seconds" +"$date_format") echo "Tag '$tag' created by $tagger at $date" git cat-file tag $3 | sed -n '5,$p' echo |