yogi_Count responses per hour in google forms spreadsheet

Google Spreadsheet   Post  #2194

Yogi Anand, D.Eng, P.E.      ANAND Enterprises LLC -- Rochester Hills MI     www.energyefficientbuild.com.   Jun-26-2017

question by zeke29:

https://productforums.google.com/forum/#!topic/docs/83vr5nLeSp8;context-place=forum/docs
Count responses per hour in google forms spreadsheet

I have a google forms where I capture the user's email and I need to count how many responses are submitted per hour by each email (user). 

Forms enters a time stamp in the form of 

MM/DD/YYY HH:MM:SS

I assume that I just need to capture the HH part of the time stamp and count the occurrences for each email but I'm not sure how to do that. Any help? 

Thanks