Late fee Calculations

[Mak K.]

How is late fee calculated. 

Lease states:

Rent due 1st of the month. If rent not received by 3rd, a initial late fee $75 will be charged. additional $25/day thereafter for until rent and late charges are paid in full.

I use cozy to get electronic ACH payments. So if tenant pays me on 6th, my late charges should be $75+ $25 (Aug4) + $25(Aug5). 

Question#1: Should Aug 6th be included or not?

Question#2: In a scenario that Tenant pays on Aug 6th, and it bounces and I come to know on Aug 8th of bounce payment. Now tenant gets a bounced check fee per lease +$75+ Late fee till Aug 8th.

Am I doing the math correct.