Determine the number of days from 13 march 2011 to 7 December 2012, taking 2012 as a leap year.
Here's app that will do this :
https://www.timeanddate.com/date/durationresult.html?m1=03&d1=13&y1=2011&m2=12&d2=07&y2=2012
It shows 635 days from the start date to the end date, but not including the end date in the calculation
365+366-31-28-13-31+7 = 635
