Git Bash date command ignoring TZ env

Question

The date(1) command is supposed to take its timezone from the TZ environment variable.

Here's an example from the manpage:

68 mak:> date --date='TZ="America/Los_Angeles" 09:00 next Fri'
Fri Oct 20 09:00:00 GMT 2023

Taking a variation:

69 mak:> TZ='America/Los_Angeles' date
Mon Oct 16 16:03:03 GMT 2023

Except as you can see, in both cases, date(1) reported out using 'GMT'. In my case, I ran these commands at 11:03am in America/Chicago.

What I expected was times expressed via the TZ:

108 mak:> date --date='TZ="America/Los_Angeles" 09:00 next Fri'
Fri Oct 20 11:00:00 CDT 2023

And:

109 mak:>  TZ='America/Los_Angeles' date
Mon Oct 16 09:46:44 PDT 2023`

Answer 1

So even though the TZ was set, date(1) ran home to GMT, because on gitbash the default directory for the zoneinfo data was empty.

to solve this, I grabbed the data from a zoneinfo repo on github and copied the zoneinfo directory to /use/share/zoneinfo

112 mak@:> ll -d /usr/share/zoneinfo/*
drwxr-xr-x 1 mak 197121     0 Oct 16 11:30 /usr/share/zoneinfo/Africa/
drwxr-xr-x 1 mak 197121     0 Oct 16 11:30 /usr/share/zoneinfo/America/
drwxr-xr-x 1 mak 197121     0 Oct 16 11:30 /usr/share/zoneinfo/Antarctica/
drwxr-xr-x 1 mak 197121     0 Oct 16 11:30 /usr/share/zoneinfo/Arctic/
drwxr-xr-x 1 mak 197121     0 Oct 16 11:30 /usr/share/zoneinfo/Asia/
drwxr-xr-x 1 mak 197121     0 Oct 16 11:30 /usr/share/zoneinfo/Atlantic/
drwxr-xr-x 1 mak 197121     0 Oct 16 11:30 /usr/share/zoneinfo/Australia/
drwxr-xr-x 1 mak 197121     0 Oct 16 11:30 /usr/share/zoneinfo/Brazil/
...

to double check, I verified that the magic number for these (binary) files was as I expected:

114 mak:> file  /usr/share/zoneinfo/America/Chicago
/usr/share/zoneinfo/America/Chicago: timezone data (fat), version 2, 7 gmt time flags, 7 std time flags, no leap seconds, 236 transition times, 7 local time types, 24 abbreviation chars

and date(1) immediately found the data and employed it to get the correct results.

110 mak:> echo $TZ
America/Chicago
111 mak:> date
Mon Oct 16 12:08:11 CDT 2023

another double check on the --date switch behavior:

119 mak:> TZ=America/New_York date --date='TZ="America/Los_Angeles" 09:00 next Fri'
Fri Oct 20 12:00:00 EDT 2023