Calculate the difference between two dates and get the value in years? [duplicate]

Question

Possible Duplicate:
How do I calculate someone’s age in C#?

I want to calculate basically the age of employees - So we have DOB for each employee, So on the C# Side I want to do something like this -

int age=Convert.Int32(DateTime.Now-DOB);

I can use days and manipulate then get the age...but I wanted to know if there something I can use directly to get the number of years.

Answer 1

Do you want calculate the age in years for an employee? Then you can use this snippet (from Calculate age in C#):

DateTime now = DateTime.Today;
int age = now.Year - bday.Year;
if (bday > now.AddYears(-age)) age--;

If not, then please specify. I'm having a hard time understanding what you want.

Answer 2

Subtracting two DateTime gives you a TimeSpan back. Unfortunately, the largest unit it gives you back is Days.

While not exact, you can estimate it, like this:

int days = (DateTime.Today - DOB).Days;

//assume 365.25 days per year
decimal years = days / 365.25m;

Edit: Whoops, TotalDays is a double, Days is an int.

Answer 3

On this site they have:

   public static int CalculateAge(DateTime BirthDate)
   {
        int YearsPassed = DateTime.Now.Year - BirthDate.Year;
        // Are we before the birth date this year? If so subtract one year from the mix
        if (DateTime.Now.Month < BirthDate.Month || (DateTime.Now.Month == BirthDate.Month && DateTime.Now.Day < BirthDate.Day))
        {
            YearsPassed--;
        }
        return YearsPassed;
  }

Answer 4

    private static Int32 CalculateAge(DateTime DOB)
    {
        DateTime temp = DOB;
        Int32 age = 0;
        while ((temp = temp.AddYears(1)) < DateTime.Now)
            age++;
        return age;
    }

Answer 5

Math.Round(DateTime.Now.Subtract(DOB).TotalDays/365.0)

As pointed out, this won't work. You'd have to do this:

(Int32)Math.Round((span.TotalDays - (span.TotalDays % 365.0)) / 365.0);

and at that point the other solution is less complex and continues to be accurate over larger spans.

Edit 2, how about:

Math.Floor(DateTime.Now.Subtract(DOB).TotalDays/365.0)

Christ I suck at basic math these days...

Answer 6

(DateTime.Now - DOB).TotalDays/365

Subtracting a DateTime struct from another DateTime struct will give you a TimeSpan struct which has the property TotalDays... then just divide by 365