a THRU HIKE can be done in 6 years at 1 mpd or 24 years at .25 miles per day. This is a consecutive hike either NOBO or SOBO and would be certifiable by ATC. On that note, some "calander year thru hikers" take a week off the trail and return to complete their thru. this means that this 1mpd thru hiker could take a week off and do a quick 7 miles when they got back. Now the line gets really blurred...a weekender could do 7 miles of the trial every weekend which translates to 1mpd does this make the weekender a thru hiker???