How to Obtain Millisecond‑Precision Timestamps in PHP: 13‑Digit, Float, and Custom 14‑Digit Formats

The tutorial explains how to generate timestamps with millisecond precision in PHP, covering three different approaches.

First method: 13‑digit integer timestamp

<code>/**
 * Get timestamp in milliseconds (13 digits)
 * @return bool|string
 */
public static function getMillisecond() {
    list($msec, $sec) = explode(' ', microtime());
    $msectime = (float)sprintf('%.0f', (floatval($msec) + floatval($sec)) * 1000);
    return $msectimes = substr($msectime, 0, 13);
}
</code>

Calling the method and printing the result yields a 13‑digit timestamp accurate to the millisecond.

Second method: floating‑point timestamp

<code>/**
 * Timestamp – precise to milliseconds
 * @return float
 */
public static function getMillisecond() {
    list($t1, $t2) = explode(' ', microtime());
    return (float)sprintf('%.0f', (floatval($t1) + floatval($t2)) * 1000);
}
</code>

Example usage:

<code>// timestamp
$_t = self::getMillisecond();
dd($_t);
</code>

Third method: 14‑digit format (YYYYMMDDHHIISS + 3‑digit milliseconds)

<code>/**
 * Year‑month‑day, hour‑minute‑second + 3‑digit milliseconds
 * @param string $format
 * @param null $utimestamp
 * @return false|string
 */
public static function ts_time($format = 'u', $utimestamp = null) {
    if (is_null($utimestamp)) {
        $utimestamp = microtime(true);
    }
    $timestamp = floor($utimestamp);
    $milliseconds = round(($utimestamp - $timestamp) * 1000);
    return date(preg_replace('`(?<!\\)u`', $milliseconds, $format), $timestamp);
}
</code>

Example usage in a payment request array:

<code>public static function getAllInfo($reqData, PayMerchant $payConf) {
    $data = array(
        'mchntCode'      => $payConf['business_num'],
        'channelCode'    => $reqData['bank'],
        'mchntOrderNo'   => $reqData['order'],
        'orderAmount'    => $reqData['amount'] * 100,
        'clientIp'       => request()->ip(),
        'subject'        => 'goodsName',
        'body'           => 'goodsName',
        'notifyUrl'      => $reqData['ServerUrl'],
        'pageUrl'        => $reqData['returnUrl'],
        'orderTime'      => date('YmdHis'),
        'description'   => $reqData['order'],
        'orderExpireTime'=> date('YmdHis', time() + 300),
        'ts'             => self::ts_time('YmdHisu'),
    );
    dd($data);
}
</code>

The article also includes screenshots illustrating the output of each method.