In article ,
Peter Andrews wrote:

The symptons you describe exactly match the problem that I had with a new
clock (Argos about £8), it turned out the MSF signal had been off for
maintenance work. The clock actually only tries to synch every few hours so
if it fails it advances exactly four hours and then waits for some time
before trying again. Service details and other advice is available from the
National Physical Lab web page at http://www.npl.co.uk/time/msfoutages.html


Ok, thanks for the suggestions. Over night the clock again managed to set
itself to the correct time and then forgot again this afternoon (again,
exactly 4 hours slow).

Changed the battery again to a brand new one (the other was laying in the
bottom of the drawer and it is just possible that it isn't new I guess) and
all is well. If I put the old battery back in it again sets itself to exactly
4 hours slow.

I'll give it a few days with the new battery but it looks a lot healthier.
Seems like a very odd failure mode! It's not the setting function either -
when a battery is put in this winds forward to either 12, 4 or 8 oclock
before sitting waiting for the signal. This takes a few minutes before it
whizzes around to the correct time (or in the case of the old duracell
the correct time - 4 hours!

Cheers,

Darren