Designer Ilya Birman has come up with what has to be one of the most elegant, minimal perpetual calendars we’ve ever laid eyes on—at least compared to other creations which tend to look like hideous ...

Perpetual calendars, as a mechanism, are a natural extension of a watch’s function. A simple time-only watch will give you hours and minutes, maybe seconds too, every 24 hours (one single rotation of ...

“August 25 in the year 20,896 will be a Sunday,” declares Subhramanya Kadrehalli. He has designed a calendar that he claims will keep time perpetually. Mr. Kadrehalli’s perpetual calendar allows the ...