14.04 resets the time Win7 uses?

[deeppow]

I run Windows 7 64bit and Ubuntu 14.04 as separate bootable systems. After running Ubuntu and later rebooting into Windows, the time is messed up and I have to reset it. This does cause a few problems such a messing up the data SETI might upload etc. etc.

Can anyone suggest what is going on and how to fix it?

Thanks!

[ajgreeny]

One of your OSs is set in UTC the other to local time I suspect. Make sure they both use the same time setting and all should be fine again.

[Karlchen]

Hello, deeppow.

By default, i.e. unless you changed it through the Windows registry, Windows defaults to assuming the hardware clock of your machine has been set to local time. Hence Windows will consider the time which your hardware clock returns as local time and display this time. The other way round, if you change your time inside Windows, Windows will adjust the hardware clock correspondingly.

By default, i.e. unleass you changed the relevant setting, Ubuntu defaults to assuming that your hardware clock has been set to UTC. Hence Ubuntu will take the hardware time, apply the offset between UTC and your local timezone to it and display the resulting time. The other way round, if you change your time inside Ubuntu, Ubuntu will apply the offset between your local time and UTC and set the hardware clock correspondingly.

The easiest way to make Windows and Ubuntu agree on which timezone the hardware clock uses, is accepting the Windows default and make Ubuntu follow the same rule. :wink:
With root privileges edit the file /etc/default/rcS (sudo gedit /etc/default/rcS) and make sure the parameter UTC is set to "no" (UTC=no). This value will be used on next reboot.

This approach assumes that both, Windows and Ubuntu, have been set to the same local timezone.

HTH,
Karl

# assume that the BIOS clock is set to UTC time (recommended)
UTC=no

[deeppow]

Thanks Karl, that solved it.