On Sun, 28 Mar 2004, antonio montagnani wrote: > Jeff Vian wrote/ha scritto, On/il 28/03/2004 22:35: > >> Another issue might be that you are running a twin O.S. computer with > >> Windows. > >> I have to start Windows then re-boot and time is fine... > >> Any other way to have summer time set properly in a computer like this?? > > > > > > Windoze resets the _system_ time for the daylight savings time > > changes. This will be seen by booting to bios and checking the time > > there. Check while on the standard time, then again when on daylight > > time. I have 2 boxes side by side, one windoze and one FC1. The time > > is reset differently. > > > > *nix boxes adjust the offset for the DST changes and do not reset > > system time. Dual boot systems often see the problems you describe. > > This is a different way of handling the daylight savings time > > changes. To me the *nix way is better. Although both work, on dual > > boot systems one or the other OS will have time problems. > > > > If your system cannot read the localtime link as the OP said, then the > > effect you describe would be anticipated ----- you are using windoze > > to change the system time and not getting an effective use out of the > > localtime offset parameters from *nix. > > > > > > If I remember what happened, on a dual boot system (in my case Windows > ME and Fedora Core) the *nix system didn't change the time, I had to > reboot in Windows, summer time was adjusted, and then reboot the *nix > system, and then both timezone and time were correct: i do not mind > about this strange even if I am compelled to boot Window twice a year ;-) The permission issue referred to elsewhere notwithstanding (I haven't run into it), I think what happens is this: Case 1: The hardware clock is local time. - Windows: Windows always displays proper local time. If powered on at 2am on time change night, Windows adjusts the system clock and the hardware clock. If powered off at 2am, Windows adjusts both clocks on next bootup, so you had better not adjust the hardware clock when booting. (I think auto correction can be turned off in the clock config screen.) I think that any attempt to set the system clock in Windows will reset the hardware clock as well. - Linux: /etc/sysconfig/clock has UTC=no. Then Linux displays the correct time before the change. If powered up at change time, Linux adjusts automatically and displays the correct system time. When next rebooted, the correct system time is saved to the hardware clock. If powered off at change time, Linux will assume the local clock is correct, so you had better adjust it before booting. If you do adjust the clock, then the first boot of Windows after the change will incorrectly attempt to adjust the already adjusted clock (unless disabled). Case 2: The hardware clock is UTC. - Linux: /etc/sysconfig/clock contains UTC=yes. System clock will always show correct local time no matter what. Hardware clock will be set to UTC on shutdown/reboot. - Windows: Can't handle a UTC hardware clock unless the Windows timezone is GMT with no daylight adjustment. I don't boot into Windows often, so my current solution is to leave the hardware clock in UTC and set the Windows's timezone to GMT with no DST adjustment. I think the only problem with this arrangement is that the Windows system doesn't display the correct local time. So I wear a watch. -- Matthew Saltzman Clemson University Math Sciences mjs AT clemson DOT edu http://www.math.clemson.edu/~mjs
