I can’t find a built-in rails method to validate a given date. E.g., that February 30th should not be allowed for a date field. However, rails does throw an exception which you can catch and add your own error.

begin
  success = @person.update_attributes(@params[:person])
rescue ActiveRecord::MultiparameterAssignmentErrors
  @person.errors.add(:birthdate, ' entered is not a valid date')
end

Somebody let me know if I’m missing something here. It seems that since this exception is thrown that the framework would have the validation available.