Currently Deki-Wiki doesn't automatically correct the time for daylight saving time. However a work-around has been found to solve this.
This fix only works if you have console access to your server. Because of this, wik.is users will be unable to perform the steps.
$wgDefaultTimezone = date('P');
Restart dekihost (/etc/init.d/dekihost restart) and new timestamps should be the correct time.