If Darwinex server time is UTC+2 it's the same as GMT+2, the difference between the two being that GMT is a time zone whereas UTC is a time reference.
To help you to understand the nuance between them, know that UTC time will always be static but if you align on GMT, daylight saving time will be taken into account as it is a time zone.
In Paris, Madrid, Rome, Frankfurt time zone as you are in +1 hour compare to UTC and another +1 because of the daylight saving time applied during this period of the year (in which we are currently in). As you are living in Milan (if it is still the case!) it makes sense Darwinex system is aligning to your current time zone.
So you should be using BarZone = CET (where CET = 1 in Zorro);