I really need some help with the specific assignment. The user inputs birth data (YYYY MM DD) and the program tells you how old you are in days :
The outprint in co
In Java 8 and later, you could use the java.time classes such as ChronoUnit and LocalDate. Perhaps not appropriate to a homework assignment though.
long days = ChronoUnit.DAYS.between( LocalDate.parse( "1981-11-06" ) , LocalDate.now( ZoneId.of( "America/Montreal" ) ) ) ;