Solved

Time Change Help

Some advice needed 

At the moment I do my league race at 5pm UK time and when the clocks change I still want it at 5pm UK time.

I have postponed the race on the 31st March

So I now have a race on the 30th March at 5pm GMT UK time and then a race on 1st April which will be starting at 6pm BST UK time

When do I need to change time time of the race on the 1st April to 5pm BST UK time

Hi Chaz
At least 24 hours before the race starts that you want the time change on. So anytime on the 30th will work. 
You can time the change on the 30th before that race and it will not effect that race as all time changes take 24 hours to hit the system.
Just make sure you do it before the 24 hour mark of the race on the 1st, other wise that race will run at the old time and not the new time you want.

So I change it to 4pm on the 30th March then on the 1st April it will start at 5pm

Yes it will

Thanks Ian