My old bedside clock radio started gaining time on a regular basis then after a few months gave up all together. I bought a new clock radio which also gained 30-40 minutes a day, took it back and exchanged it for another - same result gaining 30-40 minutes per day. Took the clock to a friends house and l left it there overnight - worked perfectly, time spot on. Does this mean I have a problem with my electricity supply or is there some other factor that may be the cause?

make sure there is spark on spark plug

Hold the 'Clock' button until the display flashes. It will first show the year, next press on 'Clock' with show the month, then the day, then the time. Use + and - to set your time and press 'Clock' again.

Don't expect this clock to set the time by itself. It is not an atomic clock.

Take a look at this tip from Sony.
The clock-setting instructions are on page 2 of the manual.

I had the same problem but saw that someone had solved the problem by buying a new power adaptor so I tried the same.
Success!
There are some people selling new power adaptors on eBay with good return policies so I'd recommend trying this before giving up hope.

I had the same problem, that is how my problems with my beloved Phillips wake-up light started, the clock froze after having it for a little over 1 year..nothing worked so I gave up on it. I had it unplugged it for a few months over the summer.. when I turned it on again and the clock was unfrozen..?! Of course not fix-it solution for you..
But now it has new problems: It acts very strange, turns the light on and off by itself and sometimes gets this very annoying humming/buzzing sound.. which is gone when i "re-boot" it. I am sending it in for repair this week.
I simply can't survive the winter months without it!

The daylight saving time change is calendar based, and unfortunately there is no way to reprogram it to the new schedule. You'll have to make the time changes manually.

I know how you feel... it is hell to get old. Have you tried looking at second hand stores for the old original Big Ben? I changed over to electronic digital alarms with battery backup, but I'm with you... it is not the same. It is a good thing that time becomes less critical to us as we age... except having more of it. Perhaps you can go to Westclox website and click on CONTACT, and send them a message yourself. Better in your own words than mine. http://www.alarmclocksonline.com/BigBens.htm May God richly bless you.

Perhaps you've already tried this but on my atomic clock I have to select the DST option and make sure you're in the correct time zone.

digital clocks work of the frequency input of the power source so it is possible to have it adjusted by a technician
like fine tuning a radio frequency there may be a pot that can be tuned to mains frequency exactly
talk with technicians in radio or tv shops or possible some jewellers who work on electric clocks may help

Did you use the same batteries? try to use new ones... sorry i can't help you more