what is timestamp data in php code example

Example 1: timestamp php

<?php
$date = new DateTime();
echo $date->getTimestamp();
?>

Example 2: unix timestamp in php

strtotime("now");

// strtotime is a function that will take a string parameter 
// that specifies a date, and returns a unix time stamp bassed
// on that

echo strtotime("2020-02-24");

// prints: 1582502400