Hellu Edu2u,
The official hours for Ftse Future are 08.00 'til 16.30. That's the "Official" close. The market then continues 'til 17.30.
Does that help? If you're referring to option settlements, I'm not up on settlement procedure but can find out. They do have some strange ways for settlements.
ps. Just a thought, for a start have a look at some moving averages.
I've played with 21 and 55 for crossovers on 1min Ftse future. Not bad, but you must experiment. Conditions change.
Good luck,