Yes, you can make this change.
Example below:
- Luvo's current billing date is the 21st of March.
- Luvo updates his billing date on 23rd March.
- Luvo's new billing date is now the 15th
- Luvo will be billed on the day that the change is made. The prorated charges must be based on the period 21 March to 14 April. I.e., 25 days x R3.33 = R83.25
- Luvo will be billed again on 15 April for R99.