PHP check the day of the week code example
Example: php check weekday of date
$dayofweek = date('w', strtotime($date));
$result = date('Y-m-d', strtotime(($day - $dayofweek).' day', strtotime($date)));
$dayofweek = date('w', strtotime($date));
$result = date('Y-m-d', strtotime(($day - $dayofweek).' day', strtotime($date)));