[Mariner]

In many occasions to describe "calendar" future events (very similar to the "general truth" category)

The school opens on September 4th

Also, some verbs denoting activity/process/momentary events don't take the progressive aspect even if it would seem natural to use:

I can see someone through the window
*I am seeing someone through the window

I can't hear what they're saying
*I'm not hearing what they're saying

I suppose we should buy that
*I'm supposing we should buy that