I was busy today setting up a scheduled tasks to reboot all computers before deploying a security patch for Java, see http://www.zdnet.com/oracle-patches-multiple-java-zero-day-holes-increases-default-security-7000009736/.  Luckily I decided to verify my scheduled task was setup properly on a client computer before assuming all will go to plan.  Turns out scheduled tasks through group policy preferences is rather unreliable so you have to do some tweaking to make it actually run at the correct time…especially when running the task near midnight where you can be off a whole day versus just one hour.  There is a hotfix for this type of issue on Vista / Windows Server 2008, but I’m on Windows 7 / Server 2008 R2 and evidently this issue was never fixed.  Also, I double checked and my server and clients were in the same time zone.

As an example, today is January 15th and I wanted to reboot all computers at 11:30 PM tonight.  In order to get this correct date / time for my client computers I actually have to set the scheduled task for January 16th at 11:30 PM.  Confusing…you bet! Here’s visual proof:

Here’s how the schedule tasks is inputted using the Group Policy editor

schedtsk1

 

 

 

 

 

 

 

 

 

 

 

 

Here’s what the task looks like in the Group Policy Management Console.  Notice how the date says 12:30 AM

schedtsk2

 

Finally, this is what the task looks like in the client, Windows 7 scheduled tasks window.  Notice how the date is 1/15/2013 now instead of 1/16/2013

schedtsk3

It took some time playing around to figure out that if I wanted the task to run on 1/15/2013 at 11:30 PM, I had to schedule the task for 1/16/2013 at 11:30 PM.  I also have a weekly scheduled task that I set to run at 9 PM and 12 AM, but client-side it actually is scheduled for 10 PM and 1 AM.  So word to the wise, check your clients to make sure they really are going to run when group policy says they are going to run.

  1. Pik says:

    Has anybody found any fix for this problem?

    I thought this is the reason:
    https://support.microsoft.com/en-us/kb/2738974

    “Assume that you configure a scheduled Windows task by using a Group Policy preference item in an environment. The environment contains a computer that is running Windows 7 or Windows Server 2008 R2. When daylight saving time (DST) changes, the start time of the scheduled task on the computer is one hour earlier or one hour later than the start time that you configured.”

    I tried applying this hotfix (http://hotfixv4.microsoft.com/Windows 7/Windows Server2008 R2 SP1/sp2/Fix405278/7600/free/451549_intl_x64_zip.exe) but it DID NOT work.

  2. Davoud Teimouri says:

    Hi,
    Is the issue not resolved by installing this KB: https://support.microsoft.com/en-us/kb/2738974?

  3. Sam S says:

    Good call!!!! I am already dealing with trying to push a powershell script via GPO as a scheduled task and to have this last item hold me back was frustrating!
    Thanks for sharing!