format-time-string bug

format-time-string bug

[Marcelo Toledo]

A few days ago I was coding something related to time, then I needed to
use the function `format-time-string´ and the code above shows what I
have found wrong:

(setq t1 (current-time))
(sleep-for 3)
(setq t2 (current-time))
(format-time-string "(%H:%M:%S)" (time-subtract t2 t1))

the result of the last expression should be something near 00:00:03.

For me it is appearing 20:00:03. For other people it's appearing
diferent values but never what I am really expecting. Could someone
please try?

time-substract is returning the correct value, in this case something
near (0 3). The data format is a list of 3 integers. The first has the
most significant 16 bits of the seconds, while the second has the least
significant 16 bits.  The third integer gives the microsecond count.

I didn't have time to identify witch function is bugged yet, but, if
someone more experienced could identify what is wrong, would be nice.

-- 
Marcelo Toledo
marcelo@marcelotoledo.org
http://www.marcelotoledo.org
Mobile: 55 71 9141-7181

Re: format-time-string bug

[Kenichi Handa]

In article <87zn9g3an9.fsf@kali.intranet>, Marcelo Toledo <marcelo@marcelotoledo.org> writes:

> A few days ago I was coding something related to time, then I needed to
> use the function `format-time-string´ and the code above shows what I
> have found wrong:

> (setq t1 (current-time))
> (sleep-for 3)
> (setq t2 (current-time))
> (format-time-string "(%H:%M:%S)" (time-subtract t2 t1))

> the result of the last expression should be something near 00:00:03.

> For me it is appearing 20:00:03. For other people it's appearing
> diferent values but never what I am really expecting. Could someone
> please try?

20:00:03 is the correct value for you because it seems that
your timezone is -0400.  As I'm in JST, I get "09:00:03".
If you want "00:00:03", you must call format-time-string as
below.

> (format-time-string "(%H:%M:%S)" (time-subtract t2 t1) t)

By the way, format-time-string is for time, not for a
period.

---
Ken'ichi HANDA
handa@m17n.org

Re: format-time-string bug

[Danilo Segan]

Hi Marcelo,

Today at 3:54, Marcelo Toledo wrote:

> A few days ago I was coding something related to time, then I needed to
> use the function `format-time-string´ and the code above shows what I
> have found wrong:

Since you're passing the value of  1970-01-01 00:00:03 in GMT as the
time-value to format-string, you probably ought to try adding optional
parameter to format-time-string: 

   (format-time-string "(%H:%M:%S)" (time-subtract t2 t1) t)
                                                          ^ note this
I somehow suspect that you're in GMT-4 timezone ;)

So, I doubt there's any bug here.

Cheers,
Danilo