ok, the difference between UTC and GMT is clear, thank you.

The most relevant poin is another Nikkey is traded in new york so ET (not JST).
I should set AssetZone in order to let my script trade that asset when the market is open. This is the point.
Lets try to recap my vps is located in London (lets say GMT) connected to a Server GMT+2 and the script need to trade several saaset one of them is Nikkey225 traded in New York-

BarPeriod = 240;
...
AssetZone = ET;
tadeThatasset;

is that all?