Tally of calls occuring during a specific time frame

Hello, I need to count the number of calls that occur during a specific time frame for a month (ie: 01:00:00 to 01:59:59). I have used a countif formula to do it automatically so i can just add in new data and get the results quickly but the totals are off by 3 when i compare it to the actuals. I highlighted the counts that are different but I cant figure out what in my formulas is causing this slight variation. Please help! Thank you!