Comment time is same as the post time

Try to use the wp_list_comments function:

http://codex.wordpress.org/Function_Reference/wp_list_comments

It allows you to control the aspect of every comment, also the replies. Then, you define a callback function, which will be called when WordPress creates each comment.

Your callback needs to start like this:

function commnents_callback($comment, $args, $depth) {
  $GLOBALS['comment'] = $comment;   
  global $post;

  // your HTML + PHP comment creation code here
}

Then, you can create the comments by using this code:

<?php if( $comments ): ?>
<ul>
<?php wp_list_comments('type=comment&callback=commnents_callback'); ?>
</ul>
<?php endif; ?>

Using this, you can control the creation of every comment.