Ghost

Hey, I was wondering if one of you wiser people could help me with a little problem I'm having. I need to be able to count the days that are between any two given dates, here is what I had, and it's wrong.

Thanks a lot.

Figured all of it out.

juliocarlosmg

a couple of months ago i had to make a Date class for the school. here you have something that may help you. perhaps you will need to change something but the idea is correct and its work. it's very simple, so, don't need any explanations.

int CountLeapYears(int startingYear, int endingYear)
{
if (startingYear < 1 || startingYear > 9999 || endingYear < 1 || endingYear > 9999)
throw new ArgumentOutOfRangeException();
if (startingYear == endingYear)
throw new ArgumentException();
int ydiff = startingYear - endingYear;
if (ydiff < 0)
ydiff = -ydiff;
return ydiff / 4 - ydiff / 100 + ydiff / 400;
}

int CountDays(DateTime dt1, DateTime dt2)
{
if (dt1 == null || dt2 == null)
throw new ArgumentNullException();
if (dt1.Year >= dt2.Year)
throw new ArgumentException();
int ydiff = dt2.Year - dt1.Year;
int c = ydiff * 365 + CountLeapYears(dt1.Year, dt2.Year) - dt1.DayOfYear + dt2.DayOfYear;
}

The Dark

juliocarlosmg: I think the big -- Closed -- text was meant to indicate that the OP didn't need any more answers.

In addition to this your CountDays function does not work. If you give it two dates with the year value less than 4 apart, it will never think there is any leap years in between them.
E.g. 2000/01/01 - 2001/01/01

I don't think you can use the difference between two years to determine the number of leap years, because once you subtract one from the other, you lose the information about whether either year was a special case (i.e divisible by 100 or 400).