- date_format: documentation ( source)
- date_modify: documentation ( source)
<?php
$issue_date = new DateTime($values['vendor_badge_issue_date']);
$issue_date_text = date_format($issue_date, 'Y-m-d');
$expiration_date = date_modify($issue_date, '+60 day');
$expiration_date_text = date_format($expiration_date, 'Y-m-d');