Get the time and date of git tags

Question

I have a project that is using git and have tagged all the releases with a tag.

$ git tag
v1.0.0
v1.0.1
v1.0.2
v1.0.3
v1.1.0

My goal is to list the releases and release dates in a web interface (tag/commit date = release date). Currently we list all the releases by using git tag.

How can I get the time and date for when the tag was made (or the commit it points to)?

Answer 1

This always worked for me:

git log --tags --simplify-by-decoration --pretty="format:%ci %d"

Consult the "PRETTY FORMATS" section of the git-log manpage for details of the format string if you want a different date formatting.

Answer 2

Use the --format argument to git log:

git log -1 --format=%ai MY_TAG_NAME

Answer 3

one can use gawk (not awk) to convert date in the "tagger" line to something human-readable:

git rev-parse v4.4-rc1 | xargs git cat-file -p | gawk '/^tagger/ { print strftime(PROCINFO["strftime"], $(NF-1)) }'

if one does not like gawk then date can be used to convert unix time:

git rev-parse v2.76 | xargs git cat-file -p | awk '/^tagger/ { print "@" $(NF-1) }' | xargs date -d

and example (dnsmasq git repo):

$ git rev-parse v2.76 | xargs git cat-file -p | awk '/^tagger/ { print "@" $(NF-1) }' | xargs date -d
Wed May 18 16:52:12 CEST 2016

Answer 4

Note that both of the above solutions get you the commit date, which can be wildly different than when that commit was tagged for release. To get the date of the tag itself, you've got to find the tag itself with rev-parse, read it with cat-file, and then parse it. A little pipeline:

git rev-parse v1.0.0 | xargs git cat-file -p | egrep '^tagger' | cut -f2 -d '>'

Answer 5

There is no simple option in git tag command to do this. I found most convenient to run

git log --decorate=full

to list all commits including tags if there are some. For listing only commits that are tagged use

git log --decorate=full --simplify-by-decoration

For details use

git help log

Answer 6

One more option:

git for-each-ref --format="%(refname:short) | %(creatordate)" refs/tags/*

See https://git-scm.com/docs/git-for-each-ref#_field_names for format options

%(creatordate) gives the date of the commit pointed to, to see the date the tag was created on use %(taggerdate)

You can incorporate the shell directly:

$> git for-each-ref --shell --format="ref=%(refname:short) dt=%(taggerdate:format:%s)" refs/tags/*

ref='v1.10' dt='1483807817'
ref='v1.11' dt='1483905854'
ref='v1.12.0' dt='1483974797'
ref='v1.12.1' dt='1484015966'
ref='v1.13' dt='1484766542'
ref='v1.2' dt='1483414377'
ref='v1.3' dt='1483415058'
ref='v1.3-release' dt='' <-- not an annotated tag, just a pointer to a commit so no 'taggerdate', it would have a 'creator date'.
ref='v1.3.1' dt='1483487085'
ref='v1.4' dt='1483730146'
ref='v1.9' dt='1483802985'