Changing rent payment date - whats the best way to do it?

Tax Planning and Financial

We have a tenant who's rent payment date is the 22nd of the month. They wanted to change the payment to the 1st of the month. We accepted but said that they must pay the difference between the old date (22nd) to the new payment date (1st of the month). we did this by prorataing the monthly rent i.e. daily rate for the rent x difference between payment dates in days.

I was wondering how other landlords dealt with such a request? Is there a better way to do this than the way we are currently doing it?

Any advice very much appreciated,

Kerry