/**
 * 獲取最近七天所有日期
 */
function get_weeks($time = '', $format='Y-m-d'){
    $time = $time != '' ? $time : time();
    //組合數據
    $date = [];
    for ($i=1; $i<=7; $i++){
        $date[$i] = date($format ,strtotime( '+' . $i-7 .' days', $time));
    }
    return $date;
}

執行結果

print_r(get_weeks());
 
 
Array
(
    [1] => 2018-06-13
    [2] => 2018-06-14
    [3] => 2018-06-15
    [4] => 2018-06-16
    [5] => 2018-06-17
    [6] => 2018-06-18
    [7] => 2018-06-19
)