Seasonal World Clock

A clock inspired by the traditional Japanese Wadokei, which was used during the Edo period. The dial changes with the seasons and latitude, making it a unique clock that lets you see the length of daylight around the world at a glance. (This app is not intended to be a historically accurate reproduction of the structure or operation of traditional wadokei clocks.)

== What is a Wadokei? == A wadokei is a traditional Japanese clock used during the Edo period. It was designed to indicate time according to the Japanese temporal hour system. In this system, the time from sunrise to sunset was considered daytime, and the time from sunset to the next sunrise was considered nighttime. Each period was divided into six equal parts. Because the lengths of day and night vary depending on the season and latitude, the length of each temporal hour also changes. This is why the system is known as a "temporal hour" system. This app draws its clock face based on the sunrise and sunset times of a selected location, and displays the current temporal hour and the length of each hour. Although this way of telling time is no longer used in daily life, it offers a unique opportunity to experience local perceptions of time that differ from the uniform hours used today.