the time is just from the server that AB runs on. I assume that it's located in the UK (check yourself if you like), but it can easily be 5 minutes out. it's not mission critical, so it doesn't really matter.
Could be too many AB'ers showin up late for work. It is probably a community service clock setting so it doesn't get shut down for contributing to the delinquency of miners and factory workers.
BillyNoMates, the clock is definitely set to UK time. It's around 10 PM here in Greece, and my posts are clocking in at around 8 PM (we are 2 hours ahead of the UK)