Discounted "Early Payment";defacto LATE payment PENALTY;Thoughts?

[Parker Fairfield]

I recall a long time (20 yrs?) ago reading a book about rentals, and how most states have made it illegal to charge a 'late payment penalty' on tenants that pay late .... 

And that the author recommended saying something like
RENT = 1300
EARLY PAYMENT DISCOUNT = 300

EARLY PAYMENT MEANS 15 DAYS before rent is due.

There for, if the tenant routinely pays the rent 15 days prior to its due date, then they get a discount ....

The other upsides are that the SECURITY DEPOSIT and LAST MONTHS rents quantity is higher.

Is anyone doing this? How many days earlier?