OS X 10.10 and later only. This script will reset the Start and (optionally) the Stop Time of the selected tracks--or all the tracks of the selected playlist--to "0:00" and (optionally) their entire duration, respectively.
You might also be interested in Batch Trim Start or Stop Time (Seconds).
Choose to reset the tracks Start Time to 0:00 and, optionally, the Stop Time to the full duration of the track
Perhaps Also of Interest...
downloaded 9m 57s ago
Recreate a playlist such that its visible columns mirror the Music library
downloaded 19m 34s ago
Append user-entered text to beginning or ending of selected tag of each selected track
downloaded 20m 52s ago
Three scripts assist with editing Work and Movement tags
downloaded 39m 50s ago
Play through each track in a playlist at your set interval
downloaded 40m 52s ago
Batch-edit playlists' Love and Dislike settings
downloaded 51m 5s ago
Apply selected CD's CD Text to its disc and track tags