Hodinkee:

As of WatchOS 6, which was introduced last September, there is a new Solar watch face. This one is simply called the Solar Dial, and it is a remarkably charming thing. It has been described as a miniature sundial for the wrist, but it is rather more like having a sundial and the Sun itself on your wrist, both at the same time.

The Solar Dial consists of a 24-hour dial with 12 (noon) at the top and 24 (midnight) at the bottom. An hour hand moves once around the dial per day, and attached to the hour hand is miniature representation of the Sun. The portion of the dial that’s in light blue represents the number of daylight hours, and the portion in dark blue, night; the boundaries between each section mark sunrise and sunset. Opposite the Sun on the 24-hour hand is a smaller dial which shows the hours and minutes, in either an analog or digital format.

I love Hodinkee’s obsessiveness with watches. The article also includes an interesting discussion of the different Twilights – not the YA novels but of sunrise and sunsets.