GogenZZo

SELECT city FROM bases WHERE site_id=1 GROUP BY city HAVING MAX(status) = 0

<?php

$inputs = [
  [
    ['Пн', '08:00 - 20:00'],
    ['Вт', '08:00 - 20:00'],
    ['Ср', '08:00 - 20:00'],
    ['Чт', '08:00 - 20:00'],
    ['Пт', '08:00 - 20:00'],
    ['Сб', '08:00 - 18:00'],
    ['Вс', '10:00 - 15:00'],
  ],

  [
    ['Пн', '08:00 - 19:00'],
    ['Вт', '08:00 - 19:00'],
    ['Ср', '08:00 - 21:00'],
    ['Чт', '08:00 - 20:00'],
    ['Пт', '08:00 - 20:00'],
    ['Сб', '08:00 - 18:00'],
    ['Вс', '10:00 - 15:00'],
  ],
];

function is_consecutive(array $numbers)
{
  $count = count($numbers);

  if ($count < 2) {
    return false;
  }

  $first = $numbers[0];
  $range = range($first, $first + $count - 1);

  return $numbers === $range;
}

function format_day_times(array $input)
{
  $timeIndexes = [];

  foreach ($input as $index => list($day, $time)) {
    $timeIndexes[$time][] = [$index, $day];
  }

  $result = [];

  foreach ($timeIndexes as $time => $data) {
    if (is_consecutive(array_column($data, 0))) {
      $result[] = sprintf(
        '%s-%s: %s',
        $data[0][1],
        array_slice($data, -1)[0][1],
        $time
      );
    } else {
      foreach ($data as list(, $day)) {
        $result[] = sprintf('%s: %s', $day, $time);
      }
    }
  }

  return join(', ', $result);
}

foreach ($inputs as $input) {
  echo format_day_times($input), PHP_EOL;
}

Пн-Пт: 08:00 - 20:00, Сб: 08:00 - 18:00, Вс: 10:00 - 15:00
Пн-Вт: 08:00 - 19:00, Ср: 08:00 - 21:00, Чт-Пт: 08:00 - 20:00, Сб: 08:00 - 18:00, Вс: 10:00 - 15:00