Bug 156697 - Linux time doesn't match Apple's summer time
Linux time doesn't match Apple's summer time
Product: Fedora
Classification: Fedora
Component: system-config-date (Show other bugs)
powerpc Linux
medium Severity medium
: ---
: ---
Assigned To: Nils Philippsen
Depends On:
Blocks: fedora-ppc
  Show dependency treegraph
Reported: 2005-05-03 10:16 EDT by Andrew Cagney
Modified: 2007-11-30 17:11 EST (History)
1 user (show)

See Also:
Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of:
Last Closed: 2006-04-07 06:05:37 EDT
Type: ---
Regression: ---
Mount Type: ---
Documentation: ---
Verified Versions:
Category: ---
oVirt Team: ---
RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: ---

Attachments (Terms of Use)

  None (edit)
Description Andrew Cagney 2005-05-03 10:16:52 EDT
Given "System clock uses UTC" disabled.

It would appear that Apple keeps the hwclock in local standard time. even during
summer.  The system clock being adjusted by an hr during summer.

GNU/Linux, on the other hand, appears to think that the hwclock should always
exactly match local time.  During summer this puts GNU/Linux and Apple one hr out.
Comment 1 David Woodhouse 2005-05-03 10:33:42 EDT
Apple stores the UTC delta in XPRAM, and I believe the kernel's RTC driver
automatically compensates for it -- thus you should be telling userspace that
the system clock _does_ use UTC.

Can you show the output of 'dmesg | grep GMT'?
Comment 2 Andrew Cagney 2005-05-05 21:23:49 EDT
Many reboots later (this really scrambles the clock):

System clock uses UTC disabled: Apple==21:xx; Linux=20:xx
System clock uses UTC enabled: Apple=21:xxx; linux=16:xx

GMT Delta read from XPRAM: -300 minutes, DST: off
Comment 3 Nils Philippsen 2006-03-14 10:45:15 EST
Guys, I really don't think this is a s-c-date problem, can you please change it
to something more appropriate (don't ask me what is more appropriate -- I would
have changed it by myself if I knew).
Comment 4 Nils Philippsen 2006-04-07 06:05:37 EDT
I can't fix this in system-config-date, I think this can only be fixed in
util-linux (hwclock) or the kernel. Pick which one you like best ;-).

Note You need to log in before you can comment on or make changes to this bug.