PHP：将日期转换为datetime并将其插入到mysql数据库中？

Question

I have an input field in my html page that gets Date from jQuery datepicker.

The format looks like this:

18/02/2017

I have a MYSQL field which is DATETIME

I need to insert the Date above into this MYSQL field.

So i tried this code:

$mysqlDate = date('Y-m-d H:i:s', strtotime($_POST['php_date']));

but the result of $mysqlDate is this:

1970-01-01 01:00:00

Could someone please advise on this issue?

Thanks in advance.