Yes, but I have given examples—I didn't read the full paper—of sessions that lasted less than a day. I've given examples of prorogation that lasted a year. If I wanted to give examples of lengths of sessions, I could go up to over three years, or again, less than a day.
My mind has a seizure at the thought of trying to write a Standing Order that would permit a prorogation after less than a day's session or prorogation lasting almost a year, or sessions that are less than a day or sessions that are three years long.
At some point, we have to accept that we can't specify all the events and reasons that are going to affect these things.