- date_default_timezone_set: documentation ( source)
- date: documentation ( source)
- strtotime: documentation ( source)
<?php
date_default_timezone_set('Europe/Berlin');
echo date('c', 1477787400) . PHP_EOL;
echo date('c', strtotime('+1 second', 1477787400)) . PHP_EOL;
echo (strtotime('+1 second', 1477787400) - 1477787400) . PHP_EOL;