Web servers lock up

I am having issues with the web servers locking up and not responding for up to 20 or 30 minutes. This only happens on the days we do Time entry before payroll, so normally once every two weeks.

I am guessing that the problem is related to using the go to end button, but any other thoughts would be greatly appreciated.

If this is the problem - Go to End, Can anyone think of a way I can tell when it is getting used, with what application, and with which user. I really need to find the person doing this and provide some education. I am reluctant to turn on debugging as we are already having performance issues during this time and the debugging will just make it slower.