/// <summary>
 /// Accepts a Nullable birthday and returns an age
 /// </summary>
 /// <param name="value">Nullable birthday</param>
 /// <param name="defaultValue">A default if value is null</param>
 /// <returns>A string expressing the relative age</returns>
 public static string ToStringAge(this Nullable <System.DateTime> value, string defaultValue)
 {
     if (value != null)
     {
         return(Extensions.ToStringAge(value.Value));
     }
     else
     {
         return(defaultValue);
     }
 }