Oanda MT4 Time- confused about backtesting

Hello,

I live in the middle east…
Oanda = US time (UTC/GMT -5 hours) in MetaTrader 4.
My Local time = UTC/GMT +2 hours

I was backtesting May/June/July… my back testing was trades on specific time which is 00:00 based on Oanda old history…

The problem is …

We have Winter (-1) and Summer (+1) times…
What should be my time while back testing in November which is winter time here in my country? should it be 23:00, 00:00, 01:00 based on Oanda history?

is it the same in the US ? Winter and Summer times? and does Oanda old history chart time change if so ?
Im realy confused …