What are some common pitfalls when converting German date formats to UNIX timestamps using PHP's strtotime function?

When converting German date formats to UNIX timestamps using PHP's strtotime function, a common pitfall is that the function may not recognize the German date format. To solve this issue, you can set the locale to German before calling strtotime. This ensures that strtotime understands the German date format and can successfully convert it to a UNIX timestamp.

setlocale(LC_TIME, 'de_DE');
$date = '31.12.2021';
$timestamp = strtotime($date);
echo $timestamp;