We have many leases with escalations that run across years. For example a lease may start in March and be $1000/month for 15 months. It then may escalate to $1250 for 15 months. What we need to be able to do is calculate the income for the current calendar year (taxes, budgets, etc).
I'm not sure where to start. It needs to be calculated for each lease and to be able to be summed for all leases.