506 Bad argument. The month index number must be an integer number between 1 and 12 inclusive.
507 Cannot change the value of the Appearance property. The Appearance property is read only at run time. You must change the value of this property from the property sheet at design time.
508 Cannot change the value of the BorderStyle property. The BorderStyle property is read only at run time. You must change the value of this property from the property sheet at design time.
509 Bad argument. The day index number must be an integer number between 1 and 7 inclusive.