TimeSpan age = today - birth //.NET FCL should guarantee this as preciseĭouble ageInDays = age.TotalDays //total number of days. Solution for 1 is obvious: DateTime birth = DateTime.Parse('') ĭateTime today = DateTime.Today //we usually don't care about birth time Calculate Generally perceived age - people usually do not care how old they exactly are, they just care when their birthday in the current year is. Calculate Exact age - in years, months, days, etc.Ģ. Public static int Age(this DateTime birthDate, DateTime laterDate)Īge -= Convert.ToInt32(laterDate.Date < (age)) ĭateTime birthDate = new DateTime(2000, 2, 28) ĭateTime laterDate = new DateTime(2011, 2, 27) Ĭonsole.WriteLine('Birth date: ' + birthDate.AddDays(i).ToString(iso) + ' Later date: ' + laterDate.AddDays(j).ToString(iso) + ' Age: ' + birthDate.AddDays(i).Age(laterDate.AddDays(j)).ToString()) ġ. / The date on which to calculate the age. / Calculates the age in years of the current System.DateTime object on a later date. Public static int Age(this DateTime birthDate) 0 is returned for a future date of birth. / Calculates the age in years of the current System.DateTime object today. Int age = birthDate.Age() public static class DateTimeExtensions By this you can obtain the age in the simplest possible way: Net nor any official rule supports this, nor does common logic explain why some born in February should have 75% of their birthdays in another month.įurther, an Age method lends itself to be added as an extension to DateTime. is the birthday of leaplings but neither. of leap years and obtain the correct result of the 28th of Feb.

The simple answer to this is to apply AddYears as shown below because this is the only native method to add years to the 29th of Feb. Public int CalculateAgeWrong2(DateTime birthDate, DateTime now) Return new DateTime(now.Subtract(birthDate).Ticks).Year - 1 Here you have the methods: public int CalculateAgeWrong1(DateTime birthDate, DateTime now) MessageBox.Show(string.Format('Test ',ĬalculateAgeWrong1(bDay, now), // outputs 9ĬalculateAgeWrong2(bDay, now), // outputs 9ĬalculateAgeCorrect(bDay, now), // outputs 8ĬalculateAgeCorrect2(bDay, now))) // outputs 8 Here is a test snippet: DateTime bDay = new DateTime(2000, 2, 29) ĭateTime now = new DateTime(2009, 2, 28)

How to get system date in cl program