As batteries die in older Macs their ability to keep the computer’s clock ticking dies with them. Slight interruptions in power can reset the date to January 1, 1970, or January 1, 2000, for newer machines.
Syncing the computer’s clock to a network NTP time server can quickly return it to current time without any effort. However, Macs may not begin syncing right away. That’s a problem for users in Active Directory environments where a discrepancy in time of more than five minutes won’t allow them to log in.
Using Apple Remote Desktop (or an SSH connection to the computer), a remote administrator can issue two simple commands to restart time syncing.
First, verify the time of the remote computer using ARD’s Send UNIX command to get the current time and date. Simply enter the
date command and run it as root.
This will return something like: Thr Jan 1 10:56:37 CDT 1970. Active Directory won’t allow any logins.
To correct the time use the systemsetup command to turn time syncing off and then turn it on again:
systemsetup -setusingnetworktime off
systemsetup -setusingnetworktime on
date command again and the clock should now show the current time: Tue Oct 30 11:09:26 CDT 2012. Active Directory users should be able to log in immediately.
To store this quick command for later select Save as Template… from the Template drop down menu and assign it a name.