C#: Calculate difference between two dates (number of days)?

Question

I see that this question has been answered for Java, Javascript, and PHP, but not C#. So, how might one calculate the number of days between two dates in C#?

Answer 1

Assuming a and b are of type DateTime:

(a - b).TotalDays

Answer 2

Use TimeSpan object which is the result of date substraction:

DateTime d1;
DateTime d2;
return (d1 - d2).TotalDays;

Answer 3

I think this will do what you want:

DateTime d1 = DateTime.Now;
DateTime d2 = DateTime.Now.AddDays(-1);

TimeSpan t = d1 - d2;
double NrOfDays = t.TotalDays;

Answer 4

     DateTime xmas = new DateTime(2009, 12, 25);
 double daysUntilChristmas = xmas.Subtract(DateTime.Today).TotalDays;