Chapter 2, Problem 20P

Develop a well-structured function to determine the elapsed days in a year. The first line of the function should be set up as

$\text{function nd= days }\left(\text{mo, da, year}\right)$

where $\text{mo = the month }\left(1-12\right),\text{ da= the day }\left(1-31\right)\text{ and year = the }$ year. Test it for January 1, 1999; February 29, 2000; March 1, 2001; June 21, 2002; and December 31, 2004.