There's a way of calculating the Julian day daynum of a year: the ordinal number of any date within the year. (January 1 is always Julian day 1.) Use int arithmetic and assume that 1 is the value of month for January, 2 for February, and so forth:

(a) daynum=31(month1)+day

(b) If the month is after February subtract (4(month) + 23)/10 **[no final parenthesis]

(c) If its a leap year and after February 29, add 1 Do the calculation assuming the entered year is NOT a leap year (skip step (c)).

Implement this as a method public static int julian(int day,int month,int year) which returns the Julian day of its date argument. Define a main() method which reads the date from the user as three separate int values, then calls your function and prints the result. You don't have to verify that it's valid.

d) add the leap year calculation and validate the input, printing an error message if it isn't a valid date.