echo "<p>今天是：" . date("Y/m/d") . "</p>";
echo "<p>今天是：" . date("Y.m.d") . "</p>";
echo "<p>今天是：" . date("Y-m-d") . "</p>";
echo "<p>今天是：" . date("l") . "</p>";
echo date('Y-m-d H:i:s').' '.date("l");