The turret clock is a small edition of the Great Westminster Clock (Big Ben) and was erected by the parishioners to commemorate the Diamond Jubilee (60 years) of Queen Victoria's reign on 20 June 1897. 

The clock strikes every hour and marks the quarter hours from 11am to 7pm with Westminster chimes.  It is usually stopped for a day when we move in and out of British Summer Time.  It is also usually stopped for our Remembrance Sunday Service.

Unfortunately the clock is very sensitive to temperature and gets excessively slow when the temperature is very high (so we stop and then start the clock at the right time when the weather cools).

Update 24 March 2021: The clock is running approximately to time.  It will be stopped on Saturday afternoon and started again at the same time on Sunday when the clocks go forward an hour.