Korean designer Jeong Yong is pleased to present his latest project, "a table calendar composed with three differently-sized rings." Simply called "ONE," the series of rings represents the date with indicators on each ring: one for the month, one for the day of the month and one for the day of the week.
The rings are held together by magnets such that the intersection point of the three rings indicates today's date.
At first, I was under the impression that ONE was somehow motorized, but that is clearly not the case. (There are a number of obvious mechanical challenges: for example, how would it skip the 31st on months with 30 days?) It's an interesting concept for sure, but more as a sort of real-life visualization of time than a practical calendar.
See also: Sasa Clock & The Present