Sun and Moon shows the time based on the position of the Sun or Moon in the sky on the watch face.

The crescent shaped sky on the dial represents 12 hours, with the hours running from left to right: When the sun is next to the leftmost marker the time is 6am. The sun slowly climbs in the sky until it reaches the apex of the crescent, at which point the time is midday. The sun then gradually descends until it reaches the right hand marker at 6pm. After 6pm the Sun 'sets' and disappears from view, meanwhile the Moon 'rises' on the left. The position of the Moon in the sky therefore shows the hours from 6pm until 6am.

Along with the image of the Sun and Moon, the hour disk features a revolving image with scenes of the natural world that gradually passes as the day progresses. The minutes are displayed in the center dial and these run in the conventional way, so each marker on this dial corresponds to five minutes.

Sun and Moon is a revival of an ancient watch design: "Sun and Moon" watches were first produced in Britain in the late 1600s during a period of experimentation with ways to represent the time. This period of experimentation eventually settled down and the concentric hour and minute hands became established as the universal standard.

The watch comes packed in an MJW box which features a newly commissioned artwork by illustrator Fanny Shorter. Inspired by the 24 hour mechanism, Fanny's artwork shows the life cycle of the Mayfly which takes just 24 hours.