Sand has been used to keep track of the passage of time since antiquity. But using sand to make a persistence of vision digital clock (English ... digits you want to display.

Not that the present situation and the abundance of free time that many are experiencing has anything to do with [Leo Fernekes] all-transistor digital clock build, which he started a year ago ...

The bright LED lights spell out the approximate time so it feels much more human than a digital display. The words clock is definitely a conversation piece, but its uses can also be more ...