Find the day of the year
This program finds the day of the year by adding together the number of days in each previous month. It uses several functions: A function to get the date, a function to determine if it is leap year, and another function to calculate the Julian date. The Julian date is the day of the year: January 1st is the 1st
day; February 1st is the 32nd day. The date is checked for valid year, month and day.