Jams may not be eligible for display in our calendar for a variety of reasons. There’s only so much space on the screen to display jams so we try to highlight things that we think are interesting to a perspective viewer.
If you put up a mostly empty page, and have no audience for your page then it’s unlikely we would be promoting it for discovery.
Jams that go for a very long time (over one month) may not appear in the calendar during certain times to prevent them from permanently taking up a row in the display.
Hope that helps