Mac OS X on x86 Hardware 2008–2024 Technical Archive
InfiniteMac OSx86 › Snow Leopard 10.6 › win 7 and osx keep changing the damn time
21,644 reads · 2009-10-29 – 2009-12-12

win 7 and osx keep changing the damn time

so i set both windows 7 and osx snow to san francisco/pacific standard time so they should both think I am in the same area and show the exact same time that is saved in the bios, yet when I boot into osx it shows the clock wrong, off by…

Primary Author
@spalek83 Published 2009-10-29
Collection
Snow Leopard 10.6
Archival Footprint
21,644 historical reads · 11 curated field notes (from 17 dispatches) · 2009-10-29 – 2009-12-12
Credited Voices (10)
@spalek83 (5)@Imkantus (2)@mormegil (2)@thorazine74 (2)@SportsGuy@brlock@maya77@NIZGTR@raykreisel@yusofu

so i set both windows 7 and osx snow to san francisco/pacific standard time

so they should both think I am in the same area and show the exact same time that is saved in the bios, yet when I boot into osx it shows the clock wrong, off by 12 hours or more. if I change it to the correct time of course windows time is off. I know I could make them both connect to the internet and change the time, but that not only dosn't always work, it is irrational.. do others deal with this, and how? it drives me crazy

how do I force osx to just show the time that is in the bios correctly?

Author Updates & Technical Revisions

Follow-up dispatches by @spalek83

Author Update #1 @spalek83 2009-10-29

disabled auto update time and set gmt time in osx.. so simple

Author Update #2 @spalek83 2009-10-29

from what i've read, the vista registry whatnot causes some problems for people, and having windows handle actual time and osx do gmt and not auto change time works so perfectly, I wonder why someone would even consider the registry change

Author Update #3 @spalek83 2009-10-29

i'm gonna try it tonight anyways... not having osx set to gmt seems like something good to have

thanks maya

Author Update #4 @spalek83 2009-10-30

so i used the windows bootcamp patch and it works. also installed the zeph patch but i'm not even sure what that does/did

but I have osx to pst time now, and windows showing it as well so thanks!

Synthesized Community Field Notes

11 technical responses curated from 17 original dispatches

Field Note #1 @SportsGuy 2009-10-29

That happens to me, too! But in Vista... I'll see if I can find anything

edit: I set it to not change the time automatically, but idk how it will work with having the right time in both OS's

Field Note #2 @brlock 2009-10-29

That is because OSX always sets the system clock to GMT and then displays the corrected time of your time zone. Windows saves on BIOS whatever your time is, disregard of time zone.

You can find a fix for windows here (weblogs.asp .net/dfindley/archive/2006/06/20/Set-hardware-clock-to-UTC-on-Windows-_2800_or-how-to-make-the-clock-work-on-a-Mac-Book-Pro_2900_.aspx) or you disable the "Set date & time automatically" in OSX and adjust your time zone to gmt.

Field Note #3 @mormegil 2009-10-29

It also screws up with any world clock you have set up though

It's the fault of osx imo. Why set system clock to be gmt and complicate things?

Field Note #4 @Imkantus 2009-10-29 ↳ Re: @mormegil
@mormegilIt also screws up with any world clock you have set up though It's the fault of osx imo. Why set system clock to be gmt and complicate things?

For me it works perfect to change my clock to Dublin / Ireland (GMT+0:00) to have correct time on Snow Leopard and XP during the winter - I no longer have it changing - don't ask me why, I just tried till it worked and there is no other fix applied.

Field Note #5 @thorazine74 2009-10-29 ↳ Re: @mormegil
@mormegilIt also screws up with any world clock you have set up though It's the fault of osx imo. Why set system clock to be gmt and complicate things?

I would say its a matter of not agreeing whats right or not giving you a choice like some linux distros do.
Google for AppleTimeService from Bootcamp. Alternatively there is also a registry hack for vista to set the hardware clock to gmt.

Field Note #6 @maya77 2009-10-29

Here is a simple fix for Windows which will keep your time accurate (taken from BootCamp):

rapid share.com/files/225861324/AT_Fix_10.zip

Simply install and enjoy.
No need to set any options.
Uninstall supported.

Field Note #7 @mormegil 2009-10-30 ↳ Re: @spalek83
@spalek83from what i've read, the vista registry whatnot causes some problems for people, and having windows handle actual time and osx do gmt and not auto change time works so perfectly, I wonder why someone would even consider the registry change

If you set up your system to be gmt, all the world clocks you might have set up to show the time in different parts of the world will be useless. Unless you're really living in gmt timezone of course.

Field Note #8 @NIZGTR 2009-10-30

or u can use this fix from Zeph Mega Share.com/1579290

works for me every time

Field Note #9 @thorazine74 2009-10-30

Having OS X time zone as GMT is not really a solution IMO. I had no troubles with Windows set up to make the system clock based on GMT but you could always use AppleTimeService in Windows, thats supposed to work with zero troubles (it does on Macs so...)

Field Note #10 @raykreisel 2009-11-02

localtime-toggle.pkg

The easiest fix that I have found is a small package called "localtime-toggle.pkg"

The original download link does not work any more so I am giving another link

krei sels.com/ray/mystuff/Localtime-Toggle.pkg

Just set your Mac OS timezone as you would normally, and set your Windows time zone as you would normally. Install this package in Mac OS, and it takes care of everything and leaves you with the correct time zone and the correct time.

good luck...

Field Note #11 @yusofu 2009-12-12 ↳ Re: @spalek83
@spalek83so i set both windows 7 and osx snow to san francisco/pacific standard time so they should both think I am in the same area and show the exact same time that is saved in the bios, yet when I boot into osx it shows the clock wrong, off by 12 hours or more. if I change it to the correct time of course windows time is off. I know I could…

Dear Spalek83,

Relax, relax . . . . OS X collects and writes clock from/to BIOS directly !
Tuning can be done with these :-

- Pls correct your clock to ur current time first.
- Use a Terminal,
- type sudo nano /etc/rc.local
- type in ur password
- type date `date -u +%m%d%H%M%Y`
- type Ctrl O (to save)
- type Ctrl X (to exit)
- type sudo nano /etc/rc.shutdown.local
- type date -u `date +%m%d%H%M%Y`

- [look at the differences, will ya !]

- type Ctrl O (to save)
- type Ctrl X (to exit)
- restart if you wish to check clock in Win7 and restart again to SL.

(DO NOT miss any single character above - otherwise it may not work)
Well, upon next restart SL will be abit a bit lag to show ur tuned clock but if u click ur clock up there, the correct time will be displayed.

Don't worry, the script won't brick ur OS X.

Credits to ALL MENTORS around the GLOBE.

Corroborated & Participated: @Imkantus
Sources & Contributor Provenance (10 credited usernames · Thread #4551)
UsernameDossier ContributionDispatchesActive Window
@spalek83Primary Author52009-10-29 → 2009-10-30
@ImkantusContributor22009-10-29
@mormegilContributor22009-10-29 → 2009-10-30
@thorazine74Contributor22009-10-29 → 2009-10-30
@SportsGuyContributor12009-10-29
@brlockContributor12009-10-29
@maya77Contributor12009-10-29
@NIZGTRContributor12009-10-30
@raykreiselContributor12009-11-02
@yusofuContributor12009-12-12