The unit period is the length of time between payments.
In most loans it would be one month. If you have a loan close on the 15th, you would have one unit period and 15 odd days for the 1st payment stream. If you have a real estate loan with an interest credit e.g. 2 days, then you would have 0 unit periods and 28 days until the first payment. (assuming loans closing in 30 day months) Yes, it is correct, because the 2nd payment stream starts XX months (unit periods) after the loan begins. They are autofilled.
There is a definition in the Help box on APRWIN. if you have any other questions, please send me a PM.
_________________________
Integrity. With it, nothing else matters. Without it, nothing else matters.