how to find out what people celebrated their birthday this year

[blaster123]

how to find out what people celebrated their birthday this year, if we have the current month and day, and we have the birth day, month and year of the person?

[salem c]

Read a pair of y/m/d into variables
Apply https://www.cplusplus.com/reference/ctime/mktime/ to each ymd
Use https://www.cplusplus.com/reference/ctime/difftime/ to figure out a 'before or after' relationship between them.