Advanced Pro-rata Billing
1. We would like to have a instant payment (Pro-rata Invoicing), but only on the amount of day until
28th, and every 28th after first payment.
2. Have options to choose Pro-rata Billing for Pricing cycle, for instance, apply Pro-rata billing only
for monthly pricing cycle and not yearly from same product.
3. The pro-rata invoice would be generated using a formula similar to: Price Per Day * Number of days until Pro-rata Date = Pro-rata invoice total.
When this logic is applied we should have correct Pro-rata invoice for the chosen invoice date.