Combine data from multiple rows

Hello, 

I am working with a very large dataset, 94,000 rows. Each row is a specific action per client and the time stamp. For example: 

Client Name      Location      Action           Date&Time

AA                     Wing A        Change         05/10/2019 0800

AA                     Wing A        Stop              05/10/2019 0815

AB                     Wing B        Change         05/10/2019 0700

What I want to do is summarize for each client

(1) how many changes occurred in a given time period 

(2) How many clients had changes in less than 1 hour

(3) I would like to graph this globally and per location 

Is there a way to do this with Pivot tables or should I create another sheet and column to extract this information?

Thank you!