I bought this for my father, who is in his 90s and whose memory is starting to fail. He had been forgetting the day and date, leading to much distress and mental confusion. I felt what he needed was a good, clear calendar clock where the day and date were prominent and easy to read. Most of the digital models seemed too complex and too small to be of real help, but the Karlsson seemed to combine virtually everything I was looking for. It has indeed proved to be a great success and has helped my father enormously, giving him back much of his self-confidence. Despite its largely mechanical nature, I can confirm that this clock is programmed to recognize which months have 30 and 31 days, and I believe the only manual intervention needed is to adjust for the leap year. My only criticism would be that the plastic case is a little flimsy and the two rounded clip-on end caps are rather too easily dislodged. My father managed to do this whilst carrying it between rooms, and inadvertently changed the date. This has been solved by mounting the clock on the wall above the doorway where it is easily seen but tamper proof.