Changing the time zone/clock in the EFI?

Discussion in 'Mac Basics and Help' started by DivineEvil, Oct 19, 2009.

  1. DivineEvil macrumors regular

    Feb 7, 2009

    I bought my Macbook from the US, but now I've returned to my country and since then ,I think, when I'm not connected to the Inet the clock is way off.

    In the PC's the system clock can be easily changed in the BIOS and if I don't have Internet the clock is currect. +- a few seconds aren't that big of a difference.

    And here is an example:
    I put my laptop to sleep. Go to school, but there is no WiFi, It's ,let's say, 12:34PM. The clock in Mac OSX, Windows 7 shows 10:15 AM. (The times are for example). As soon as I go online, the clocks are adjusted via or depending on the OS. And the clock shows the currect time of ,in this example, 12:34 PM.

    Is it possible to set the time zone/clock in the EFI boot system similar to the BIOS in the PCs?

    I'm currently using rEFIt as boot manager and there there is a Shell console...
  2. BlueRevolution macrumors 603


    Jul 26, 2004
    Montreal, QC
    The problem is that Mac OS X stores the time in UTC and Windows in your local time zone. It's UTC-7 here, so when it's 12:00 the system stores 19:00 and subtracts 7 hours. Windows sees that 19:00 and assumes that it is the correct time.

    I don't think there's anything you can do about that. Even Boot Camp relies on the workaround of updating system time online, as you've noticed.
  3. MacUser2525 macrumors 68000


    Mar 17, 2007
    Search on "set windows to UTC" set/create the registry key you will find then it should be using the same time as OS X without needing to update from a time server hopefully this corrects the problem.

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