This script produces the background for a 24-hour wall clock. Sunrise and sunset times for the summer and winter solstices are included for a particular location.

• python 3.5.2
• matplotlib 1.5.1
• numpy 1.11.1

Clone this repo using https://github.com/mkudija/Clock.git.

I found out about 24-hour watches (such as those from No-Watch and Jacopo Dondi) with a single hour hand that makes one full revolution in 24 hours. What I like about this concept is the ability to see the entire day at a glance.

The website 24hourtime.info gives a great overview of the design of 24 hour timepieces. One design consideration mentioned is whether to place 12 (noon) or 24 (midnight) at the top of the dial. My optinion is that the intitive solution is to put noon at the top and midnight at the bottom, which matches how we observe the sun moving throughout the day. Jacopo Dondi also points out how a 24 hour watch can be used as a compass.

If you can see the entire day, why not also show the sunrise and sunset time? If on a smartwatch, you could pull the sunrise and sunset time for your current location. As a first step, I wanted to make a clock face that shows the sunrise and sunset times at the summer and winter solstices for a given location.

My design places midnight at the bottom and noon at the top to present an intuitive view of the day with respect to the movement of the sun. Sunrise and sunset times at the winter solstice (shortest day of the year) are represented by the dark grey shaded region. Likewise, sunrise and sunset times at the summer solstice (longest day of the year) are represnted by the lighter grey shaded region. Notice the offset between these regions, representing the hour adjustment for daylight savings time. The location is also printed on the clock face because these times are location-dependent. I also include, in red numerals, 12-hour representation for the p.m. hours for ease of use for those used to 12-hour time.

The clock face is generated by running wall-clock.py.

I bought a 24-hour clock movement, printed the clock face, adhered it using Mod Podge and a foam brush.

Here is the result: