PHP 相對時間格式化：X 分鐘前、Y 天前

<?php
function plural($n) { return $n!=1 ? 's' : ''; }
function getRelativeTime($date) {
    $diff = time() - strtotime($date);
    if ($diff < 60) return "$diff 秒".plural($diff)." 前";
    $diff = round($diff/60);
    if ($diff < 60) return "$diff 分鐘".plural($diff)." 前";
    $diff = round($diff/60);
    if ($diff < 24) return "$diff 小時".plural($diff)." 前";
    $diff = round($diff/24);
    if ($diff < 7) return "$diff 天".plural($diff)." 前";
    $diff = round($diff/7);
    if ($diff < 4) return "$diff 週".plural($diff)." 前";
    return "on ".date("F j, Y", strtotime($date));
}
echo getRelativeTime('2024-01-15 10:30:00');
?>

輸出範例：20 分鐘前、3 天前、2 週前、超過一個月顯示完整日期。