Photos with circular artifacts

Tis the season to decorate. I've been putting up the tree off and on for the past week. Decided today to decorate outside instead. Its really cold so I should've stayed inside but I didn't. After I got the outside done I thought I'd take a few shots with an old Yashica that I picked up at an auction. It seems to work but until I get a processed film back I won't know for sure. So I won't trust Christmas pictures to it. I had a film in the camera so the number of shots left was limited. I used the rest of the roll taking pictures of what I'd accomplished or messed up outside (depends on your worldview, I suppose). However I decided to take just a few with the digitile camera. That camera was upstairs in our house so I retrieved it and as I was going down the back stairs I took a shot down the stairs and again when I reached bottom, I shot back up the stairs. It was getting dark outside when I shot the outdoors decorations. The digitile seems to be a lot more light sensitive than the films I use. Anyway, when reviewing the digitile photos I quickly realized that the pictures I took of the stairs in the house BOTH have the strange artifacts and they are rather clear and easily spotted on the tiny monitor. I printed both and discovered my printer is out of all but blue ink; none the less, the artifacts show up clearly. Two in each photograph. Is there anything special about December 9th?So far these circular features have only shown up at Halloween and December 21st (shortest day) until now on December 9th. I will not know whether the film cameras show anything until the film is processed. I haven't checked the outside shots I made with the digitile in any detail as yet but, unlike the interior shots, I didn't notice anything on the monitor. Once I get a new ink cartridge I can check the outside shots better.