Custom date not showing correctly when using date_i18n

I am unable to display a custom date using date_i18n

It will only display the date and time of now.

For example, I have a date of 2013-07-29 15:07:25 but I get 2013-07-30 15:37:06

$date = '2013-07-29 15:07:25'
echo date_i18n('D j M, Y g:i:s a', strtotime($date))

If I was to do date_i18n('D j M, Y g:i:s a', strtotime($post->post_date)) it would work fine but not a custom date from let’s say a post meta value.

Any help to get this working or show what I am doing wrong would be most appreciated.

Thank you.