Non-traditional lease term for college town rentals

I own/manage properties in a collage town that does not adhere to a traditional year-lease including both the term and payments.

Leases are done based on the school year, so August 22, 2019 - May 17, 2020. Rent is paid semesterly, so $10,000 due July 1st and $10,000 due December 1st for the upcoming semester. Additionally, the leases are signed 18 months in advance, so as of February 2020, I already had a new lease signed for August 2021 - May 2020 which results in a current 19-20 lease, a 20-21 lease for new students and a 3rd lease for the 21-22 students. I’m unable to enter any future information into the system to keep track of expected income, dates, or deposit, which is a problem because for a period of 5 months a year, I’m holding the deposits on 3 different leases.

Stessa currently does not (from what I can see) allow for any modification of the rent as it can only be inputted as a monthly rate. While the lease term dates can be modified, because they’re not full months, I’m not even able to divide the full lease amount by the number of days to determine a monthly rent, nor would that be reflective of the accuracy in a rent roll.

It would be great to be able to have modification in the frequency and allocation of rent.