Calendars recommended for the elderly need to have the following characteristics: the first one is easy to use, the UI is as simple as possible, the buttons are large, and it is best to have sound. The second is the function, which has both the solar calendar and the lunar calendar, as well as the reminder function. The third is to minimize external links, because the elderly are easy to press other places by mistake. If you advertise, put it at the beginning. The fourth calendar has a health reminder function. The fifth calendar has the function of memory customization. I believe this kind of calendar is very popular with the elderly.