mysql_datetime.js

var d = new Date();
var mysqlDate = d.getFullYear() + '-' + (d.getMonth() + 1) + '-' + d.getDate() + ' ' + d.getHours() + ':' + d.getMinutes() + ':' + d.getSeconds(); // 2001-03-10 17:16:18 (the MySQL DATETIME format)

mysql_datetime.php

// remember: date() return time in UTC (GMT+00)
$mysqldate = date("Y-m-d H:i:s");  // 2001-03-10 17:16:18 (the MySQL DATETIME format)

$phpdate = strtotime( $mysqldate ); // convert mysql datetime format to date (php)
$mysqldate = date( 'Y-m-d H:i:s', $phpdate ); // convert date (php) to mysql datetime format
$mysqldate = \Carbon\Carbon::createFromTimeStamp(time())->toDateTimeString() // equivalent, using Carbon

// using Carbon, convert "28/10/2015 23:59:59" (timezone GMT+07) to timestamp (UTC: GMT+00)
$expired_date = \Carbon\Carbon::createFromFormat('d/m/Y H:i:s', "28/10/2015 23:59:59", 'GMT+07'); // return 2015-10-28 23:59:59
echo date('c', $expired_date->timestamp); // 2015-10-28T16:59:59+00:00

// using Carbon, convert "28/10/2015" (timezone GMT+07) to timestamp (UTC: GMT+00), note: time is current (ex: 01:10:19 GMT+07)
$expired_date = \Carbon\Carbon::createFromFormat('d/m/Y', "28/10/2015", 'GMT+07'); // return 2015-10-28 01:10:19
echo date('c', $expired_date->timestamp); // 2015-10-27T18:10:19+00:00 (note: 27)

// using Carbon,convert "28/10/2015" without defining timezone to timestamp (UTC: GMT+00), note: time is current (ex: 01:10:19 GMT+07)
$expired_date = \Carbon\Carbon::createFromFormat('d/m/Y', "28/10/2015"); // return 2015-10-28 18:10:19
echo date('c', $expired_date->timestamp); // 2015-10-28T18:10:19+00:00 (note: 28)

use_datetime_when_need_store_date_and_time.txt

mysql> show variables like '%time_zone%';
+------------------+---------------------+
| Variable_name    | Value               |
+------------------+---------------------+
| system_time_zone | India Standard Time |
| time_zone        | Asia/Calcutta       |
+------------------+---------------------+

mysql> create table datedemo(
    -> mydatetime datetime,
    -> mytimestamp timestamp
    -> );

mysql> insert into datedemo values ((now()),(now()));

Use DATETIME instead of TIMESTAMP
ref: http://stackoverflow.com/questions/409286/datetime-vs-timestamp

mysql> select * from datedemo;
+---------------------+---------------------+
| mydatetime          | mytimestamp         |
+---------------------+---------------------+
| 2011-08-21 14:11:09 | 2011-08-21 14:11:09 |
+---------------------+---------------------+

mysql> set time_zone="america/new_york";

mysql> select * from datedemo;
+---------------------+---------------------+
| mydatetime          | mytimestamp         |
+---------------------+---------------------+
| 2011-08-21 14:11:09 | 2011-08-21 04:41:09 |
+---------------------+---------------------+