homecomputerlab

First, add your favourite internet time servers to your router, you can get a nice list of publicly available NTP time server here: http://www.timetools.co.uk/ntp-servers/ref/ntp-server-uk.htm

ntp server xxx.xxx.xxx.xxx (prefer)
ntp server yyy.yyy.yyy.yyy

Then add daylight saving time config to the router:
clock timezone gmt 0
clock summer-time BST recurring last Sun Mar 1:00 last Sun Oct 2:00

It may also be worthwhile setting up your Cisco router as a time server with the following command:
ntp master 3

You can then manually add your ‘ntp master’ routers’ ip address to other routers as a time server, it may also be a good idea to lock this down with a related acl.

You can view your routers ntp sync status with the following commands:
show ntp status
show ntp associations

Finally you might also want to add your router as an ntp server so that any dhcp clients in your environment will also receive the correct time with the following dhcp option:
option 42 xxx.xxx.xxx.xxx