you could do a simple count down based on your frame rate.
If your frame rate is 30fps then 60 frames is 2 seconds for example.
code:
//if your putting all the code on the movie clip
onClipEvent(load){
countDown = 60;
}
onClipEvent(enterFrame){
if(countDown > 0){
countDown--;
}else{
//what to do after timer
}
}
times are approximate due to differences in users processor speed so you can't set your watch by it or anything.