Re: TZ ignored by (display-time)

Re: TZ ignored by (display-time)

[Jason Rumney]

> (display-time) fails to take the contents of TZ into effect when
> formatting the time string.


The problem seems to be caused by the new display-time-world 
functionality, so this bug shouldn't affect Emacs 22.

When time.el is loaded, the following code clobbers the internal 
timezone setting:

(defcustom display-time-world-list

  ;; Determine if zoneinfo style timezones are supported by testing that

  ;; America/New York and Europe/London return different timezones.

  (let (gmt nyt)

    (set-time-zone-rule "America/New York")

    (setq nyt (format-time-string "%z"))

    (set-time-zone-rule "Europe/London")

    (setq gmt (format-time-string "%z"))

    (set-time-zone-rule nil)




According to the documentation for set-time-zone-rule, it should set the 
timezone back to the local timezone when the argument is nil. But it 
doesn't seem to take note of the TZ environment variable when it does this.

Re: TZ ignored by (display-time)

[James Cloos]

>>>>> "Jason" == Jason Rumney <jasonr@f2s.com> writes:

JimC> (display-time) fails to take the contents of TZ into effect when
JimC> formatting the time string.

Jason> The problem seems to be caused by the new display-time-world
Jason> functionality, so this bug shouldn't affect Emacs 22.

Jason> According to the documentation for set-time-zone-rule, it should
Jason> set the timezone back to the local timezone when the argument is
Jason> nil. But it doesn't seem to take note of the TZ environment
Jason> variable when it does this.

Cool.  Thanks for tracking it down.

Running (set-time-zone-rule (getenv "TZ")) does indeed cause
the (display-time) output to match the timezone specified by TZ.

I looked at the set-time-zone-rule DEFUN as well as set_time_zone_rule()
in src/editfns.c but am not sure how best to fix this....

-JimC
-- 
James Cloos <cloos@jhcloos.com>         OpenPGP: 1024D/ED7DAEA6

Re: TZ ignored by (display-time)

[Jason Rumney]

Jason Rumney wrote:
> According to the documentation for set-time-zone-rule, it should set 
> the timezone back to the local timezone when the argument is nil. But 
> it doesn't seem to take note of the TZ environment variable when it 
> does this.

I've now changed the trunk so that the initial value of TZ is saved so 
it can be restored in the above case.