This is something that's been bothersome to us for a while. Let's say you have a five-year campaign pledge that someone starts paying. But let's say in 2015, they pay with stock so the actual value of the gift might be higher than the current 2015 installment. This affects the following year's pledge installment (2016). Now, let's say they don't get their pledge installment in in 2016. The database currently won't allow you to reschedule pledge payments that are partially fulfilled (in the example, the 2016 pledge installment). Instead, it ignores this pledge and won't give you the option to set up an irregular re-scheduled pledge system. This is important because when we send out reminders, it goes off of the pledge installment amount owed for that year. If nothing was changed, the 2016 installment would just be dropped and the system wouldn't actually recognize that the full pledge wasn't paid. 

Another tricky thing is people who say they want to pay a pledge monthly, but then decide to do an annual or semi-annual payment system. This would be accomplished if it were possible to reschedule the pledge using an Irregular installment schedule, but the database doesn't allow for the Irregular option when rescheduling.

Ideally, it'd be great to have more flexibility in rescheduling pledges and to allow these partially-paid pledges to be moved to the end of the pledge schedule or somehow altered.