removing data from timetable which do not occur continously

hello

I have a timetable with some data I call S4. S4 is minutely data for a whole month and there can be more then 1 entry of S4 for a minute. I want to keep the data for s4 which have occured for at least 3 continuous minute and remove the ones which did not.

can someone help me with this? I tried a number methods but so far was unsuccessful.

[Peter Perkins]

Sarvesh, it's likely that this is straight-forward, but your description is not clear. Give a short clear example of what you have, and what you want to end up with.