What are some common issues when working with timestamps in PHP and MySQL databases?

One common issue when working with timestamps in PHP and MySQL databases is the difference in timezone settings between the two. To solve this issue, it is recommended to set the timezone for both PHP and MySQL to the same value, typically UTC.

// Set the timezone for PHP
date_default_timezone_set('UTC');

// Set the timezone for MySQL
$mysqli = new mysqli('localhost', 'username', 'password', 'database');
$mysqli->query("SET time_zone = '+00:00'");