Your solution is simple.
When you optimise and then backtest using server time, this will give you the trading times for your settings in UTC+0 or GMT, you then find out what these are for your local timezone.
If your optimise settings show 08:00 and 12:00, this will be for UK GMT, you just find out the equivalent for your local timezone, if its 4 hours ahead then it will be 12:00 and 16:00
I think that's what you have been trying to say.
PS: If you are using a VPS, you need to use the VPS location timezone.