这会将第一个唯一的工作日复制到新数组中，如果该工作日重复，则只会添加事件ID。

$events = [
    [
        \'week-day\' => \'tuesday\',
        \'day-date\' => 1511841600,
        \'events_ids\' => [83417]
    ],
    [
        \'week-day\' => \'wednesday\',
        \'day-date\' => 1511913600,
        \'events_ids\' => [83417]
    ],
    [
        \'week-day\' => \'thrusday\',
        \'day-date\' => 1512000000,
        \'events_ids\' => [83417]
    ],
    [
        \'week-day\' => \'tuesday\',
        \'day-date\' => 1511830800,
        \'events_ids\' => [83417]
    ]
];

$new_events = [];

foreach ( $events as $event ) {
    if ( array_key_exists( $event[\'week-day\'], $new_events ) ) {
        // If we have this week day just merge the event ids.
        $new_events[$event[\'week-day\']][\'events_ids\'] = array_merge(
            $new_events[$event[\'week-day\']][\'events_ids\'],
            $event[\'events_ids\']
        );
    } else {
        $new_events[$event[\'week-day\']] = $event;
    }
}

$new_events = array_values($new_events);

如果初始数组中的事件不是仅来自一周的事件，则应关注day-date - 将所有事件ID与之关联，然后您可以轻松获得该唯一日期的工作日名称。这种方法将更加通用。