why am i returning 00 error php code example

Example 1: time to string in php

<?php
$date = '27/06/2020, 04:42:43 PM';
$date = str_replace('/', '-', $date);
echo date('F j, Y, g:i a',strtotime($date));

// output : June 27, 2020, 4:42 pm
?>

Example 2: php start of day epoch

$beginOfDay = strtotime("today", $timestamp);
$endOfDay   = strtotime("tomorrow", $beginOfDay) - 1;