Get part is System action for Date object that gets the month, date or year from a date variable and puts it in a Text variable or number variable.
Symptom: Ceritfy will allow the user to put the result (the month) in a date variable but when the step is executed, it will fail with the error message Invalid data. Cannot convert '10' to Date for variable Myresults (where '10' represents October).
Solution: The results for the Get part action has to be either a text variable or a number variable – not a date variable.