code: public static function isCzechHoliday($date)
      {
          if (!$date instanceof DateTime) {
              if (\is_int($date)) {
                  $date = new DateTime('@' . $date);
              } elseif (\is_string($date)) {
                  $date = new DateTime($date);
              } else {
                  throw new RuntimeException(self::poorManTranslate('fts-shared', 'Invalid date format'));
              }
          }
  
          $holidays = ['01-01', '05-01', '05-08', '07-05', '07-06', '09-28', '10-28', '11-17', '12-24', '12-25', '12-26'];
  
          if (\in_array($date->format('m-d'), $holidays, true)) {
              return true;
          }
  
          //Easter
          $easterDays = easter_days($date->format('Y')); //Return number of days from base to easter sunday
          $easter = new DateTime($date->format('Y') . '-03-21');
          $easter->add(new \DateInterval('P' . $easterDays . 'D')); //Sunday
          $easter->sub(new \DateInterval('P2D')); //Friday
          if ($date->format('Y-m-d') === $easter->format('Y-m-d')) {
              return true;
          }
          $easter->add(new \DateInterval('P3D')); //Monday
  
          return ($easter->format('Y-m-d') === $date->format('Y-m-d'));
      }
docs: Whether the specified date is Czech holiday
  
  @param string|DateTime|int $date Any valid date or datetime
  
  @return bool Is holiday
  @throws \Exception
  @throws RuntimeException
  @static