C# calculate accurate age

public static class DateTimeExtensions
{
    public static string ToAgeString(this DateTime dob)
    {
        DateTime today = DateTime.Today;

        int months = today.Month - dob.Month;
        int years = today.Year - dob.Year;

        if (today.Day < dob.Day)
        {
            months--;
        }

        if (months < 0)
        {
            years--;
            months += 12;
        }

        int days = (today - dob.AddMonths((years * 12) + months)).Days;

        return string.Format("{0} year{1}, {2} month{3} and {4} day{5}",
                             years, (years == 1) ? "" : "s",
                             months, (months == 1) ? "" : "s",
                             days, (days == 1) ? "" : "s");
    }
}

See the answers at How do I calculate someone’s age in C#? for ideas.

Not certain that it would always be correct (haven't thought about if there's some cases with leap years etc that might make it fail...), but this is an easy way to get out the year and month:

DateTime bd = DateTime.Parse("2009-06-17");
TimeSpan ts = DateTime.Now.Subtract(bd);
DateTime age = DateTime.MinValue + ts;
string s = string.Format("{0} Years {1} months {2} days", age.Year -1 , age.Month - 1, age.Day - 1);