Massachusetts Landlords--Late Fee question--Conflict with BP form

Hey all,

Purchased Mass Landlord forms right here from BP... trying to help a buddy out who bought his first home that has an in-law apartment. The lease I purchased states: 

"Any payments paid after the _____ day of any calendar month shall be deemed late. Any late payments shall be charged a $______ late fee for the first day rent is late. An additional fee of $_______ per day shall be assessed for each additional day Rent is late, until Rent is paid in full."

Everything I've found says you cannot charge a late fee until after 30 days. Can anyone shed some light on this? These are supposed to be written by attorneys....