Extension method to get the age in years

Need to work out the lapsed time in years between a date and now? This is how!

        public static int CalculateAge(this DateTime dateTime)
            var age = DateTime.Now.Year - dateTime.Year;
            if (DateTime.Now < dateTime.AddYears(age))
            return age;

Extension methods are easy to chain, simply call like this...

         int years = DateTime.Now.CalculateAge();