Does the "Edit" time clock take into account the value in "Default Time Offset"?

The server that hosts our forum is an hour ahead, so I set the "Default Time Offset" to "-1". It correctly updated the time displayed with the posts. BUT, all of the regular users lost their ability to edit their posts within the 20 minutes they are allowed to do so. When I reset the "Default Time Offset" to "0" users had the "Edit" feature back and working correctly.