上周一

if (date('w') == 1){ //当前周一时的处理$sMondayDay = date('Y-m-d',strtotime('last monday')); //当前周一，取上周一
}else{ //当前不是周一时处理$sMondayDay = date('Y-m-d',strtotime('-1 week last monday')); //当前非周一，取上前推一周取周一
}
echo "<br>";
echo '上周一的日期::'.$sMondayDay;
echo "<br>";

上周日

//上周日
echo '上周日:' . date('Y-m-d', strtotime('-1 sunday', time())); //上一个有效周日,同样适用于其它星期
echo "<br>";

本周一

//本周一
echo '本周一:' . date('Y-m-d', (time() - ((date('w') == 0 ? 7 : date('w')) - 1) * 24 * 3600)); //w为星期几的数字形式,这里0为周日
echo "<br>";

本周日

//本周日
echo '本周日:' . date('Y-m-d', (time() + (7 - (date('w') == 0 ? 7 : date('w'))) * 24 * 3600)); //同样使用w,以现在与周日相关天数算
echo "<br>";

指定日期的上周一

$qipa250_day = '2024-04-10';
$qipa250_week = date("w", strtotime($qipa250_day)); // 星期
if ($qipa250_week == 0) {$qipa250_week = 7;
}
$qipa250_n = $qipa250_week - 1 + 7;
$qipa250_zhouyi = date('Y-m-d', strtotime("-{$qipa250_n} days", strtotime($qipa250_day)));
echo "<br>";
echo $qipa250_day . "的上周一是:" . $qipa250_zhouyi;
echo "<br>";

指定日期的上周日

$qipa250_day = '2024-04-10';
if ($qipa250_week == 0) {$qipa250_week = 7;
}
$qipa250_n = $qipa250_week + 7 - 7;
$qipa250_zhouri = date('Y-m-d', strtotime("-{$qipa250_n} days", strtotime($qipa250_day)));
echo "<br>";
echo $qipa250_day . "的上周日是:" . $qipa250_zhouri;
echo "<br>";

指定日期的本周一

$qipa250_day = '2024-04-10';
echo $qipa250_day . '-是周' . $qipa250_week = date("w", strtotime($qipa250_day)); // 星期
if ($qipa250_week == 0) {$qipa250_week = 7;
}
$qipa250_n = $qipa250_week - 1;
$qipa250_ben_zhouyi = date('Y-m-d', strtotime("-{$qipa250_n} days", strtotime($qipa250_day)));
echo "<br>";
echo $qipa250_day . "的本周一是:" . $qipa250_ben_zhouyi;
echo "<br>";

指定日期的本周日

$qipa250_day = '2024-04-10';
echo $qipa250_day . '-是周' . $qipa250_week = date("w", strtotime($qipa250_day)); // 星期
if ($qipa250_week == 0) {$qipa250_week = 7;
}$qipa250_n = $qipa250_week - 7 ;
$qipa250_ben_zhouri = date('Y-m-d', strtotime("-{$qipa250_n} days", strtotime($qipa250_day)));
echo "<br>";
echo $qipa250_day . "的本周日是:" . $qipa250_ben_zhouri;
echo "<br>";