i found this bug. example i config time zone in joomla to +7 in global config, when i post comment, time in comment is faster 7 hour. i resolve this problem by edit file joscomment\utils.php
from
660 global $mosConfig_offset;
661 return(date($format, strtotime($strdate)+($mosConfig_offset*60*60)));
to
660 //global $mosConfig_offset;
661 return(date($format, strtotime($strdate)));
I not sure this right way. but it resolve my problem.