Get and parse string from json to php

$dateonly = "/Date(1234)/";
echo $dateonly = preg_replace("/[^0-9,.]/", "",$dateonly);

I don't think this is JSON, or at least not a valid one. Nonetheless, you can extract numbers like this:

preg_match_all('!\d+!', stripslashes("/Date(1234)/"), $output);
echo $output;

This format /Date(1234)/ usually called JSON Date Format. It contain unixtime with miliseconds. So, when you extract the number you need to divide it to 1000 to get the unixtime and process it in PHP. Here I give a function to extract the date and convert it to PHP DateTime Object

function parseJSDate($jsDateObject)
{
    $dateTime = null;
    if (preg_match("/\/Date\((\d+)\)\//", $jsDateObject, $match)) {
        if (isset($match[1]) && is_numeric($match[1])) {
            $timestamp = (int) $match[1];
            $dateTime  = new \DateTime();
            $dateTime->setTimestamp($timestamp / 1000);
        }
    }

    return $dateTime;
}

$date = parseJSDate("/Date(1224043200000)/");
echo $date->format("Y-m-d H:i:s");