If your station's SoundExchange reports are processed by NPR then you send them, among other things, a Playlist Log conforming to NPR's specification.
NPR playlist logs have one row per spin and six columns:
Title | Artist | Album | Label | Start Time | End time
Spinitron does not have an end time field and instead has duration. When we prepare an NPR playlist log, we calculate end time for each spin by adding its duration to its start time.
The calculated end time can overlap the start time of the next spin since there's nothing in Spinitron to prevent this.
NPR sometimes rejects a playlist log on the grounds that it has overlaps. We don't know their criteria exactly but we can eliminate this reason for rejection if there are no overlaps in the log. So we have a new (Oct 2018) feature to trim the end times in a playlist log that overlap the start time of the next item. This trimming does not affect your playlists in Spinitron, only NPR-format playlist logs.
You can see which spins were trimmed by exporting the playlist log instead of sending it to NPR via FTP. You can email it to yourself, download it, or copy-paste it. I found copy-paste works nicely with Excel and Google Docs. When you do this, Spinitron adds a 7th column to the table: trimmed seconds.
The trimmed seconds field is empty if the spin was not trimmed, i.e. it did not overlap the next spin. Otherwise it has the number of seconds trimmed. If you like, you can use this information to investigate the source of the overlaps and perhaps to edit your playlists. In any case, it documents the exact effect of the trim feature.
In the SoundExchange report page in Spinitron, if you choose Delivery = FTP and then press the green Upload button then Spinitron sends the adjusted playlist log to NPR with only the 6 columns required by NPR.