On 24/12/2004-11:10, Anastasia Gornostaeva wrote:

> Hello.
> 
> open Unix
> 
> let _ =
>    let curr_time = time () in
>    let curr_tm = gmtime curr_time in
>    let new_time, _ = mktime {curr_tm with tm_hour = curr_tm.tm_hour+1} in
>    let diff = new_time -. curr_time in
>       Printf.printf "%f\n%f\n%f\n"
> 	 curr_time
> 	 new_time
> 	 diff
> 
> 
> gives an negative result -7200.000000. Why? 
> 
Probably because Unix.mktime's argument is interpreted in the local time 
zone (as explained in unix.mli). You probably want to call 
Unix.localtime instead of Unix.gmtime.

HTH,
Julien