This is a nice plugin but some parts of it needs to be updated or fixed.
For those who having problem of "it says Events Calendar updated with current Facebook events but nothing happens" this is my fix.
it tries to convert unix timestamp to unixtimestamp in line 135 of sync-facebook-events.php
just change the line from (removing strtotime function)
$offsetStart = strtotime($event['start_time'])+$offset;