Frequency distribution

I would like to count The number of activities that have any portion of time in that interval

Originally Posted by 6StringJazzer

[initial response deleted]

After looking at your data, I don't think your question is well-formulated. You have activities with a Start and Stop time. For a given interval, what you do want to count?

The number of activities that start in that interval
The number of activities that end in that interval
The number of activities that have any portion of time in that interval

For questions like this it's always helpful to include a sample of what you want the result to be.