Late rent fee charged monthly or daily

I live in MD and I currently have a lease that mentions the following about late fees: "5% of the monthly rent for every day the rent is late after the 5th day rent is due".  I bough the contract from eForms.com.  My question is, can I charge 5% for everyday rent is not paid?  Or is it only 5% of the rent no matter if they are late 1 or 20 days?  I appreciate everyones guidance.