Clocks have been round since the days of sundials, reflecting the endless cycle of day to night and back. Once handheld clocks — first pocket watches, later wristwatches — became commonplace, checking one’s watch became much more common, especially in contexts where one was waiting or impatient.
The watch face became a familiar icon in the ’80s and ’90s, but in an effort to be original some platforms opted or other indications of time passing: an hourglass or “beachball.”
(Icon by Susan Kare)