How to convert time () * 1000 to string in Y-m-d H:i:s format by PHP

as mentioned, how does PHP convert time () * 1000 to a string in Y-m-d H:i:s format

Php
Jul.09,2021

<?php

date_default_timezone_set('Asia/Shanghai');

$dat = time()*1000;

echo date('Y-m-d H-i-s', $dat/1000);
echo "\n";
Menu