Fix Boot Camp time offset

Dec 4th, 2007 by Jared Schwager boot camp, time offset, Windows

Being a new Mac switcher, I of course found myself installing Windows using Boot Camp so I can run those couple applications that are only available in the Windows world. The first time I booted out of my Boot Camp partition and back into Mac OS X I noticed my time had been offset by about 5 hours. After a bit of googling I found that Windows uses a different time scheme and thus changes the internal hardware clock every time I boot into Windows which ends up screwing up the time displayed in Mac OS X the next time I boot into it.

I found a quick and easy little hack on how to fix this problem thanks to a commenter on this blog post.

First, boot into your Boot Camp partition. Open up Notepad and copy and paste the following:

@echo off net time /setsntp:tick.usno.navy.mil net stop w32time net start w32time

Save this as a .bat (batch) file. Now find your saved batch file and drag it into your “Startup” folder in your Start menu. Now every time you start up Windows, it will fix the time offset automatically.

On a side note, sorry for the very long delay in posts lately.

6 reader comments

January 11th, 2008 at 10:59 am Ted McCormick says:

I very rarely go on the internet with my Mac and have also experienced the time offset in switching between windows and Mac OS. My fix was after noticing that the offset was equal to the number of hours difference between my time zone and GMT. I simply lied to the computer setup and told both windows and Mac that my location was equal to GMT with no time offset (Monrovia). That fixed the problem and both clocks read the same local time now. Again this fix does not require the computer to go out to the web to reset it’s internal clock.
February 20th, 2008 at 3:04 am Bunthon Chea says:

Hi all

I just wonder why Apple dont fix this bug ASAP?
Above post it is a good temporary solution
But kindly post here if you have any other better or permanent solution (I dont have internet connection at home I can not syncronize time)

Thanks all
October 19th, 2008 at 6:31 am problem with my time and date in MAC OS X - MacTalk Forums says:

[...] @echo off net time /setsntp:tick.usno.navy.mil net stop w32time net start w32time Save this as a .bat (batch) file. Now find your saved batch file and drag it into your “Startup” folder in your Start menu. Now every time you start up Windows, it will fix the time offset automatically (stolen from Fix Boot Camp time offset – Grupenet) [...]
January 9th, 2009 at 9:54 am introspectif says:

It’s already 2009, but still, thank you so much for this!
February 28th, 2009 at 8:30 pm Zach Griswold says:

This might be kind of late, but there is a more permanent fix that doesn’t require an active internet connection. You can find it on the OSx86 Tips and Tricks page. If you don’t want to manually do this fix I posted an automated solution that you can download on my blog. Hope this helps someone!
January 22nd, 2010 at 10:04 pm Nathan says:

Even though its been a year since your comments,
Thanks Zach!