Algorithm to add or subtract days from a date?

Question

I\'m trying to write a Date class in an attempt to learn C++.

I\'m trying to find an algorithm to add or subtract days to a date, where Day starts from 1 and Month s

Answer 1

I would suggest writing first a routine which converts year-month-day into a number of days since fixed date, say, since 1.01.01. And a symmetric routine which would convert it back.

Don't forget to process leap years correctly!

Having those two, your task would be trivial.