path: root/templates/hooks--update
diff options
authorAndy Parkins <>2007-01-26 08:58:48 (GMT)
committerJunio C Hamano <>2007-01-28 22:35:50 (GMT)
commita69aba6af3e96f8021c194691a851e78febd70bf (patch)
tree765ec3a9bd3936cfeff42af19bf780d0e2e252ba /templates/hooks--update
parent5558e55c06a1e897f3064f0c8a343d5c9858f6b2 (diff)
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 <>
Diffstat (limited to 'templates/hooks--update')
1 files changed, 1 insertions, 1 deletions
diff --git a/templates/hooks--update b/templates/hooks--update
index 9863a80..81f706f 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'