Does anyone know the best way to group a set of Excel data by time interval
of x Seconds?

For example, if I have:
Time Count
0:16:24 1
0:16:40 1
0:16:49 1
0:16:51 2
0:17:02 1
0:17:11 1

I want to say, group and auto-sum the data for intervals of every 10 seconds
starting with the first time value. So I'd expect something like:
0:16:24 - 0:16:34 1
0:16:34 - 0:16:44 1
0:16:44 - 0:16:54 3
0:16:54 - 0:17:04 1
0:17:04 - 0:17:14 1

or I'll even take within a window of 10 seconds starting from each
successive value like:
0:16:24-0:16:34 1
0:16:40-0:16:49 2
0:16:51-0:17:01 2
0:17:02-0:17:12 2

Thanks for any help you can provide.

Jon