GMaxey, This calculation between two dates is working great. Others may be interested to see what the output looks like:
It took this long: 1 day, 22 hours, 27 minutes and 30 seconds. Thursday, August 10, 2017 9:48:13 AM

But usually, I get something like this:
It took this long: 10 minutes and 15 seconds. Thursday, August 10, 2017 9:45:49 AM

The date that it subtracts from looks something like this: 8/8/2017 11:20:42 AM