Hello!  I have been researching this for a bit and each scenario I find seems to be just enough different from what I'm looking for to confuse me.

I'm looking for a simple function that I will need again in the future so I want to learn how to write it myself without hiring a developer.

The Use Case:
Each piece of equipment requires scheduled calibrations.  In the equipment module, you can see all the information regarding the equipment included the last calibration that was performed, how often the calibration needs to be performed (presented in days), and when the next one is due.  When calibrations are performed I want to update the info so I can have the next due date automatically set.  So....

In the EQUIPMENT module:
I have a Last Calibration Performed date field

In the CALIBRATION module:
Ih ave a Calibration Completed Date field

Upon completion of calibration, I simply want to copy the Calibration Completed Date from the CALIBRATION module over to the Last Calibration Performed field in the EQUIPMENT module.

I have similar scenarios in other places so if I can get this to work and study the function logic, I can do it in other places myself.  Seems basic and I know others have done it, but everything I saw in my research required a bit more and got more complex than what I need.

Thanks!!!