The mechanism :

The green outer ring with 5 primary partitions and and 300 smaller partitions gives 59/300 turns per minute counterclockwise: 11.8 turns per hour.
The planetary gear of the seconds, in green color, is driven by the outer ring and gives 59 rph counterclockwise. And in turn, the axis makes a complete turn clockwise, rolling on the inside of the crown of the minutes, by hour.
The hand of the minutes, in blue color, turning on the central axis and linked to the axis of the planetary gear of the seconds, makes a complete turn every hour.
The wheel that rotates clockwise integrally with its base and with the hand of the minutes, make to spin counterclockwise two blue planetary wheels. These two planetary wheels spins counterclockwise a third planetary gear.
The third planetary wheel rotates one turn per hour clockwise and transmits the rotation to the fourth planetary wheel. The fourth planetary wheel spins counterclockwise and progresses clockwise.
The fourth blue planetary wheel gives 2 turns on itself and its axis gives the entire turn around the sphere of the clock every 12 hours.
On the four planetary wheels is mounted the hour hand: a big red triangle, giving rigidity to the structure and indicating the hours and rotating clockwise.
The big red triangle, linked to a freewheel on the central axis, drives the rotation of the three static planetary yellow wheels of the day. Turning counterclockwise about its fixed axis, rotates counterclockwise the yellow big crown that distinguishes the day light hours, of the darkness of the night and makes a complete turn every 24 hours.
The big red triangle, also linked to another freewheel on the central axis, drives the rotation of three static planetary wheels magenta of the week, much bigger than those for the day. Turning counterclockwise about its fixed axis, and spinning counterclockwise the crown magenta indicating the day of the week, and makes a complete turn every week.

Interaction:
Buttons:
The buttons are used to toggle the different layers of the watch:
-. Blue hand of minutes, and the green planetary gear of the seconds
-. Green crown of the seconds.
-. Static blue sphere of the hours and the minutes.
-. Planetary gear set and red triangle of the hours.
-. Planetary gear set in yellow color, and yellow crown of the day and the night
-. Planetary gear set in magenta color, and yellow crown of weekday.
-. Clock base body.

Dragging:
-. Dragging a finger, you can move the clock from its initial position.
-. Joining or separating and sliding two fingers on the screen, reduce or increase the size of the watch.
-. Dragging and rotating about the central axis with the finger on the red triangle of the hours, you can change the time. After removing the finger, the 'circadian clock', will slowly readjusting to redial the actual system time.


Circadian Clock:
www.nummolt.com

Technical drawings for the Circadian Clock:
http://www.nummolt.com/CircadianClock/
© 2014 Maurici Carbó, architect.
http://nummolt.blogspot.com/2014/03/posted-new-circadian-clock-at-google.html

Notes from developer:

The term 'circadian' comes from the Latin 'circa', meaning "around" (or "approximately"), and 'diem' or 'dies', meaning "day".
This app is only a clock, with many layers, showing many overlapped mechanisms, with zoom. The triangle of the hours is manually adjustable, and has an algorithm to reset the clock to the system time after any adjustment.
Nothing concerning the biological circadian cycle.
But one of the layers of the clock represents daylight.

There's a version in live wallpaper format.
Is a paid version:
At: https://play.google.com/store/apps/details?id=com.nummolt.circadian.clock.wallpaper