On Windows 2003 it is possible via the registry to set a custom interval for updates.
This is done via the following registry key:
HKLM\SYSTEM\CurrentControlSet\Services\W32Time\TimeProviders\NtpClient\SpecialPollInterval
After adjusting this key and then restarting the Windows Time service, when I update the time changes to (for my setting) one day from the time I clicked the update button.
What I don't know how to do is set the exact time at which the update occurs?
Best Answer
If you really want to synchronize at a specific time, your best bet would be to set the automated interval to a very, very large number, and then use the windows scheduler to run
w32tm /config /update. If I got this wrong, you can consult the official documentation.