Time mistake – difference between WP-admin and blog

Hi,

I have got a problem with the time wordpress shows to the user. The times in the blog are sometimes (not everytime) wrong. Two examples:

1.) A user posted a comment on 29.07.2008, 9:30 pm. A wrote an answer six minutes later. On the blog is written: The user posted the comment 9:47 pm, I answered at 9:00 pm. That’s quiet unlogical. First of all: The time isn’t right (the user posted the comment 20 minutes earlier) and my answer is earlier than the basic comment. But: WordPress shows them in the right order: first the user’s comment, than mine.

2.) I wrote a posting for my blog last evening. I published it 9:02 pm. On the page the time is 9:17 pm, whitch is 15 minutes later then my post.

Annotation: The time in WP-admin is always right, at the blog it’s sometimes wrong. Later comments on other posts have got the right time.

The code where the date is created:
<?php comment_author_link() ?> schrieb am <?php comment_date('d.m.Y, H:s') ?>:

What is the mistake?
Thanks for your help!