Add a 4 session time filter to a very simple EA and check the code

So I have a very simple EA. It is nothing more than a breakout EA trading donchian channels using ATR for  stop levels and a trailing stop. I've back tested 10 years data on Birts Tick Data suite on the EURUSD, GBPUSD and USDJPY with very promising results. But it looks apparent that time of day plays an important factor.

I would like to add a time filter for the four daily sessions, Asian, Europe, London and New York. I image the input parameters will resemble something like this.

extern string   Trading_Sessions       = "Use GMT";

extern int      AsianOpen              =        1;

extern int      AsianClose             =        3;

extern int      EuropeOpen             =        5;

extern int      EuropeClose            =        8;

extern int      LondonOpen             =        9;

extern int      LondonClose            =       11;

extern int      NewYorkOpen            =       12;

extern int      NewYorkClose           =       19;

I happy to provide the full source code for the EA. It is very simple (370 lines) as I built it. But then again EA's sometimes don't need to be complex. Also the custom indicator it works with, which is nothing more than a donchian channel indicator.

Testing is carried out at GMT, my brokers server time is +3 and I trade in Aust with local time +8.  So I image a time correcting would also may be necessary .

There's no need for bools like trade Asian session as  this filter is for my needs. 

 Cheers, Bob