Auto-time is only applicable when using the Start/Duration/End time control (CPB stations during their SX webcast reporting periods).

Enabled or disable auto-time (if available) with the auto checkbox in the Played table header of a playlist:

Autotime checkbox

If auto-time is enabled, when you edit the Played time or Duration of one item, the Played times of all subsequent items in the playlist are adjusted automatically.

Auto-time takes the Played time of the song you edit, adds its Duration to figure the song's end time and uses that to set next song's Played (i.e. start) time. The process repeats all the way from the item you edit to the last item the playlist (i.e. the one at the top of the display).

So auto-time can be handy if you play several songs back-to-back between announcements. You can insert gaps between songs by editing the Played time of the first song after each announcement break, working from older items (lower down) to newer items (higher up).

Note: set breaks are assumed to have zero duration