Zakaria Easy to implement? There is no easy way to just add them together. Some are one time, some are daily, some are weekly, monthly, or even less frequent. Some of my one time payments are scheduled a year from now. How much ahead do you want to add them together? Should the system always look 1 week ahead? Or 1 month? Or should the user choose a time frame? If a periodically payment occurs multiple times in a defined time frame, does it count as 1 payment?
These questions need to be answered before implementing this feature, so I don't think it is that easy.