5 ms·

Your clock messes up because your Debian and Windows are disagreeing on whether your Real Time Clock should be set in local time (Windows) or UTC time (Linux).

Your clock messes up because your Debian and Windows are disagreeing on whether your Real Time Clock should be set in local time (Windows) or UTC time (Linux). fix: timedatectl set-local-rtc 1

jeroenhd 4y ago
Alternatively, tell Windows the RTC is in UTC: https://wiki.archlinux.org/title/System_time#UTC_in_Microsoft_Windows https://wiki.archlinux.org/title/System_time#UTC_in_Microsof...
- chungy 4y ago
  That registry flag is routinely broken in various versions of Windows and hotpatches to the same version. It's not wise to rely on it.
  - edrxty 4y ago
    That seems like the kind of thing that shouldn't be broken all the time given how common of an issues this is. Perhaps it's not wise to rely on windows.
  - sertsa 4y ago
    All my home PC's dual booting linux/windows (3 I think) are set to think the hardware clock is UTC. Never had a problem, did that at least 5 years ago. Now relying on that in a production environment ...
  - jaza 4y ago
    Agreed. Don't bother trying to make Windows give Linux the time of day (pun totally intended), it never works, that's probably by design. Just give up and make Linux accommodate the Windows style system clock, has almost no issues.
  - ajolly 4y ago
    And that explains why I've had issues trying to use that reg flag Thanks for the info!
  - jeroenhd 4y ago
    Strange, I've never had trouble with it on win10 + Linux. Maybe there's a (third party) driver that messes with the RTC for some reason that doesn't always activate? Maybe I shouldn't be too surprised that Microsoft's support is broken.
rtpg 4y ago
is there any known nasty consequences from setting that? Like things I should expect
- cesarb 4y ago
  The local time can be ambiguous during a daylight savings time transition. That is, if you use local time in the RTC, and turn your computer on during that ambiguous hour, it will not know which offset should be applied. I believe Windows "solves" that by storing state in the registry, which means that dual-booting with local time in the RTC might in some cases lead to the daylight savings time transition being applied twice (whenever the other operating system has already corrected the RTC clock, but Windows believes the correction hasn't been applied yet). Using UTC (or any local timezone without daylight savings time) avoids that issue, since there's no repeated hour.
  - rtpg 4y ago
    probably not a problem for me given I'm in a jurisdiction without DST! Thanks for sharing that information

Your clock messes up because your Debian and Windows are disagreeing on whether your Real Time Clock should be set in local time (Windows) or UTC time (Linux). fix: timedatectl set-local-rtc 1

jeroenhd 4y ago

Alternatively, tell Windows the RTC is in UTC: https://wiki.archlinux.org/title/System_time#UTC_in_Microsoft_Windows https://wiki.archlinux.org/title/System_time#UTC_in_Microsof...

chungy 4y ago
That registry flag is routinely broken in various versions of Windows and hotpatches to the same version. It's not wise to rely on it.
- edrxty 4y ago
  That seems like the kind of thing that shouldn't be broken all the time given how common of an issues this is. Perhaps it's not wise to rely on windows.
- sertsa 4y ago
  All my home PC's dual booting linux/windows (3 I think) are set to think the hardware clock is UTC. Never had a problem, did that at least 5 years ago. Now relying on that in a production environment ...
- jaza 4y ago
  Agreed. Don't bother trying to make Windows give Linux the time of day (pun totally intended), it never works, that's probably by design. Just give up and make Linux accommodate the Windows style system clock, has almost no issues.
- ajolly 4y ago
  And that explains why I've had issues trying to use that reg flag Thanks for the info!
- jeroenhd 4y ago
  Strange, I've never had trouble with it on win10 + Linux. Maybe there's a (third party) driver that messes with the RTC for some reason that doesn't always activate? Maybe I shouldn't be too surprised that Microsoft's support is broken.

rtpg 4y ago

is there any known nasty consequences from setting that? Like things I should expect

cesarb 4y ago
The local time can be ambiguous during a daylight savings time transition. That is, if you use local time in the RTC, and turn your computer on during that ambiguous hour, it will not know which offset should be applied. I believe Windows "solves" that by storing state in the registry, which means that dual-booting with local time in the RTC might in some cases lead to the daylight savings time transition being applied twice (whenever the other operating system has already corrected the RTC clock, but Windows believes the correction hasn't been applied yet). Using UTC (or any local timezone without daylight savings time) avoids that issue, since there's no repeated hour.
- rtpg 4y ago
  probably not a problem for me given I'm in a jurisdiction without DST! Thanks for sharing that information