Time Difference for the purpose of math

Scriptcase 9 General
#1

I need the ability to figure out the difference of time between two fields and calculate minutes. I have a table with Session Start Time (DateTime) and Session End Time (DateTime). I need to be able to figure out the difference in minutes and then divide by 4. I need this result to then update the field “Units”. I am suer this would be done in a Event, but not sure where or how.

#2

I need the same