If you're not familiar with GMT offset, let me have a go at explaining...
If an EA needs to know the time, all it can get is the broker time that appears in the top left of your screen just above all the symbols, and it will say something like "Market Watch: 20:59:59".

That's often known as "server time" and unfortunately its not a standard for everyone, but depends on where the server is (NOT where YOU are!!). It also changes for daylight saving, so be aware.

For example, I live in Australia but my broker server is in London (I think), so my offset is 0 at the moment (again, I think), but another demo account I have is in Switzerland and that's GMT +1. If my server was in Sydney I'd probably have GMT +10, and in NYC it might be -5.

One way to sort out what you need is to look at your Windows clock and turn on the GMT option and just compare your server time with the clock. If the GMT clock says 1600 and your server time is 1700 then you're GMT+1. Another way to check is your closed trades in the Account History tab. MT will record the server time that a trade opened and closed, so we are hoping to see these trades open at 1600GMT.

If the offset time is not set right the strategy may still work, but it will be much more luck than skill. The whole point of this strategy is to take the highest and lowest price from 14-1600 GMT, so if you have a different time period you really have a different strategy.

If you are comfortable with the time thing then I encourage you to try it at different times and see how it goes. The indicator I posted ( but I didn't write it) is terrific for looking at different time periods to get a feel for it. I certainly will be testing other times, and when I get a round tuit I'll build some testing options into the EA.

Regards,

Couso