[rootbear]

Is there a reason why the path to the timezone file is prefixed with a colon?

TZ=:/etc/localtime

I've set TZ sometimes without the colon and it seem to work. I did a quick online search and didn't find anything relevant.

[avar]

:<whatever> means "read it from the <whatever>" file. See the last part of the relevant glibc documentation: https://www.gnu.org/savannah-checkouts/gnu/libc/manual/html_...

However the reason it works without : is that the implementation is being lazy and just ignores the : delimiter and falls back to parsing out a filename either way:

https://sourceware.org/git/?p=glibc.git;a=blob;f=time/tzset....

[rootbear]

You beat me to it. I was answering my own question when one of my users came in with a problem. Stupid users...

[rootbear]

Here is the answer:

https://www.gnu.org/software/libc/manual/html_node/TZ-Variab...

  The third format looks like this:

  :characters

  Each operating system interprets this format differently; in the GNU C
  Library, characters is the name of a file which describes the time zone.

The other formats specify the timezone directly, such as EST+5EDT. Interestingly, it seems to work okay without the colon. Perhaps the leading slash implies a filename?

[unwind]

See https://news.ycombinator.com/item?id=13704054. The colon forces the file to be loaded, without it the other formats are tried first.