Looking for a Calendar Package for Basic Calculations instead of Events

I’m looking for a calendar package / library in React Native or Flutter that allows me to do basic calculations rather than just adding events. For example, instead of creating events, I want to be able to add numbers—like if I add 100 every Tuesday, I want the calendar to total these entries at the end of the month automatically.

Ideally, it would be something I could use for recurring entries and basic math calculations on dates.