One might think that all ways of deriving the time of day from the sun's position in the sky have been employed by now. The bifilar dial was invented in 1922 by Heinrich Michnik, a German professor of mathematics.
Time is read at the point where the shadows of the two wires intersect.
Many variations on this theme have been developed since, with variously shaped and oriented gnomons. The bifilar dial is in fact a kind of nodal dial, be it that the point of reading is not the shadow of a material point, but is formed only on the dial face. The bifilar dial can therefore also indicate the date. The Sundial Park in Genk has several unusual dials on display. The Sundial Park website gives some background information.