HELP NEEDED FLASH 8 : Timings and using a timer to measure time

I’m going to make a game which is going to be timed not to end but just to say at the end of the game you took so many minutes to complete this game.

I want to start the timer on say the first frame and end it on another frame. then on a seperate frame to them I want to say how long it took.

Can someone suggest what code I should use and give me an example please.

Thanks in advance.