PHP的strtotime和PostgreSQL的EXTRACT(EPOCH FROM ...生成不同的输出

I send data present in my database to this third party system. It only imports dates correctly when I use PHP's strtotime * 1000:

$data = strtotime('2015-12-08 15:12:16') * 1000; // output: 1449594736000

I want to generate all data only with my PostgreSQL database, without using PHP. So I tried it:

SELECT EXTRACT(EPOCH FROM '2015-12-08 15:12:16'::DATE) * 1000; -- output: 1449532800000

By using this PostgreSQL way, the third party system imports dates wrong.

How can I generate the same output generated by PHP with my PostgreSQL database?

What could be causing this difference?

Looks like you need convert data to timestamp in UTC +2

# SELECT EXTRACT(EPOCH FROM '2015-12-08 15:12:16'::timestamp without time zone + interval '2 hour')*1000;
   ?column?    
---------------
 1449594736000
(1 row)