We are looking for a way to calculate years of giving based on campaign years, rather than based on fiscal years. For instance, if an alum makes a pledge with campaign year X, it still counts as only one year, even if they pay half of it in the following fiscal year. Or, for a different example, if an alum wants to catch up on past years when they weren't giving, we invite them to give several gifts at once; they can cover campaign years 2020, 2021, 2022, 2023, 2024 – and that's five years of giving, even though they gave all five gifts on one day. That is our longtime practice and we want to continue doing it that way after we convert. How can this be done?