PHP Milliseconds Timestamp: 3 Methods

1. Utilize the microtime function:

$time = microtime(true) * 1000;
echo $time;

1. Utilizing the DateTime class:

$dateTime = new DateTime();
$milliseconds = $dateTime->getTimestamp() * 1000 + round($dateTime->format('u') / 1000);
echo $milliseconds;

1. Utilize the gmdate function:

$milliseconds = gmdate('U') * 1000 + round(gmdate('u') / 1000);
echo $milliseconds;