I used a few of these little planners when I was in college in the late 1980s. In the photo below, which includes some of my other planners from that time, you can see a black and brown Uncalendar, and the red one in the top left with a post-it on top is also an Uncalendar.

The planners had a horizontal format:

Size comparison below vs. a pocket Moleskine:

Inside, there were undated weekly and monthly layouts, as well as some other custom pages for planning and task tracking:

These were my favorite notebooks for a while. I loved the size, the format, the thickness, the plastic comb binding, and even the somewhat cheesy plastic covers, which sometimes included a clear pocket on the outside in addition to the ones on the inside that held the calendar booklet in. One of them still has a rather amusing clipping that I’d tucked in there!

It’s interesting to look at these now, as the system almost seems like a proto-Bullet Journal format. There were instructional pages at the beginning to explain the method:

I assumed this brand was a now-extinct relic of the ’80s, but the company, People Systems Inc.,  is actually still around, and is still a family-owned independent business! You can still buy various Uncalendar planners, though they seem to have discontinued this pocket version, which is a shame. Maybe they’ll bring it back someday!