You will probably find that if you turn off your router that it looses the time that you had set. Also, you may find that the
router just looses time gradually, meaning that alarms etc are not really that accurate.
Thanks to Oliver Broad for this.
You can keep the time accurate using SNTP (Simple Network Time Protocol). All you need to know is the address of an SNTP server. In this
example i have used ntp2b.mcc.ac.uk
Log into the CLI and put in the following commands, pressing enter after each line:
create sntp servaddr dname ntp2b.mcc.ac.uk
modify sntp cfg enable
get sntp stats
The first line creates an entry telling the router the address of the SNTP server. The second line enables SNTP on the router, and the
third will give you the status of SNTP so you can check it has worked.

The router will then check periodically and update it's time so that it is always accurate. It checks every 15 minutes (I think!!)