In 2007, Konstantin Chaykin began work on the complicated table clock "Easter Computus Resurrection", in which he implemented a hand-type indicator for the date of Orthodox Easter of his own invention.

While preparing this project, he filed a patent application describing the design of such a clock, where he also mentioned a wristwatch with the same indicator and a perpetual calendar. In the same year, Chaykin created a prototype of the "Easter Computus" wristwatch and has since periodically returned to this highly challenging idea. This sketch shows a variant of the design for that very "Easter Computus" wristwatch prototype from 2007.