在 PHP 中可以通过date()获取当前时间，在>5.2的版本中最好还是用 datetime 类型
date()
<?php
echo date('Y-m-d H:i:s');
?>
DateTime
<?php
$dt = new DateTime();
echo $dt->format('Y-m-d H:i:s');
?>
更完善的方法
上面两个例子返回的当前时间都是服务器时区时间（timezone 可在php.ini中声明）
Above examples will return NOW using your server timezone, as it is defined in php.ini, for example:
[Date]
; Defines the default timezone used by the date functions
; http://php.net/date.timezone
date.timezone = Europe/Athens
最准确的方法是以UTC时间，所以
/* server timezone */
define('CONST_SERVER_TIMEZONE', 'UTC');
/* server dateformat */
define('CONST_SERVER_DATEFORMAT', 'YmdHis');
<?php
/**
* Converts current time for given timezone (considering DST)
* to 14-digit UTC timestamp (YYYYMMDDHHMMSS)
*
* DateTime requires PHP >= 5.2
*
* @param $str_user_timezone
* @param string $str_server_timezone
* @param string $str_server_dateformat
* @return string
*/
function now($str_user_timezone,
$str_server_timezone = CONST_SERVER_TIMEZONE,
$str_server_dateformat = CONST_SERVER_DATEFORMAT) {
// set timezone to user timezone
date_default_timezone_set($str_user_timezone);
$date = new DateTime('now');
$date->setTimezone(new DateTimeZone($str_server_timezone));
$str_server_now = $date->format($str_server_dateformat);
// return timezone to server default
date_default_timezone_set($str_server_timezone);
return $str_server_now;
}
?>