gistfile1.m

- (BOOL)_dateIsDisabled:(NSDate *)date
{
  // disable all dates before current date
  return [date compare:[NSDate date]] == NSOrderedAscending;
}

- (BOOL)calendar:(CKCalendarView *)calendar willSelectDate:(NSDate *)date
{
  return ![self _dateIsDisabled:date];
}

- (void)calendar:(CKCalendarView *)calendar configureDateItem:(CKDateItem *)dateItem forDate:(NSDate *)date
{
  if ([self _dateIsDisabled:date]) {
    // TODO: style me as disabled.
  }

}