I have a vCRM with a module called Time_Entries

I have a field (called Actual_Time) that uses a formula to capture the date/time the record was created. 

I want to use workflows based on this information but, zoho does not allow this functionality for formula fields so...

I created another date/time field called "Entry Time".  I want to use a function to copy the record from the Actual_Time field to the Entry_Time field...but I'm struggling defining the variables, syntax, etc.

Is there an example of this I can see.  Most of the examples I see are copy from one module to another and get overly complex for what I need.  Both of these fields are in the same module.

Thanks!