A whole-month calendar watch face, using a clever mechanical simulation.
Babylon, an analog watch face, displays a whole-month calendar using a clever mechanical simulation, including the last days of the previous month and the first days of the following month. See below for a description of the mechanics being simulated.
A setting is available to choose which day (Sunday, Monday, or Saturday) is considered the first day of the week. To change this, long press on the center of the face, or click on the gear below the face in the face chooser panel.
Two sets of red indicator wires (two horizontal and two vertical) move linearly to indicate the current day of the month (more precisely, the two horizontal indicators show the week, the two vertical ones show the weekday, and their intersection shows the current day).
A simulation of a special mechanical moon phase indicator is present at the lower left, along with a month display at the top and a year display at the lower right.
More information is available at the website listed.