Question

How do I calculate Day, Month, Year exactly?

Means..

From 2th Jan 1990 to 9th May 2009 is..

xxx Days, xxx Months, xxx Years.

Any idea how to do that?

I tried Timespan and Tick().. Both failed to do so..

Answer 1

You cannot do it through direct calculation (i.e. there’s no “TotalMonths” or “TotalYears” property of TimeSpan, simply because those numbers do not make sense with arbitrary intervals of time).

Instead, you can just count the number in a loop, like so:

var dt1 = new DateTime(1990, 1, 2);
var dt2 = new DateTime(2009, 5, 9);

int years = 0;
while (dt1.AddYears(1) < dt2)
{
    years ++;
    dt1 = dt1.AddYears(1);
}

int months = 0;
while (dt1.AddMonths(1) < dt2)
{
    months ++;
    dt1 = dt1.AddMonths(1);
}

int days = (int) Math.Floor(dt2.Subtract(dt1).TotalDays);

I haven’t tested this, so there might be off-by-one errors or whatever, but that’s the basic idea.