Offset Time on Broker

Hello, I'll get straight to the point here, there is confusion about the new expert advisor I just bought, it goes like this:

GMTOffsetOfBroker - This is the most important part. The EA uses GMT Universal Coordinated Time for its News WatchDog. If your Broker is +3 from the News Watchdog Time, then you have to shift your broker 3 hours back, in this case you set -3 in your EA setting. This is a list of brokers with their GMTOffset.

Tickmill = -3, ICMarkets = -3, FBS = -3, FxChoice = -3, Pepperstone = -3, GKFX = -3
Alpari = -3, MX = -3, ACTIVTRADES = -2 

How do I check the broker's time? If I use Instaforex, what is the time difference?
Thank you...