whmcsDNSManager/modules/addons/DNSManager2/mgLibs/custom/helpers/TimeUnitsAliassesHelper.php

<?php

namespace MGModule\DNSManager2\mgLibs\custom\helpers;

use Exception;


class TimeUnitsAliassesHelper
{
    private static $units = [
        'M' => 60,
        'H' => 3600,
        'D' => 86400,
        'W' => 604800
    ];

    /**
     * @param $val
     * @return float|int
     * @throws Exception if can't parse $val to seconds
     */
    public static function convertToSeconds( $val )
    {

        if (preg_match('/^\d+$/', $val))
        {
            return (int)$val;
        }
        preg_match('/(\d+)([MHDW])/i', $val, $matches);

        if (!$matches)
        {
            throw new Exception('Wrong TTL Syntax for: '.$val);
        }

        $secondsPerSingeUnit = static::$units[strtoupper($matches[2])];
        $amount              = (int)$matches[1];
        return $secondsPerSingeUnit * $amount;
    }
}