Use with Kids to practice telling time or to demonstrate how Planetary gear systems work. 
The center gear is at a ratio of 1:11 with the outer frame which produces a 1:12 reduction total. 

Use a color change at layer to make the hour hand and numbers pop in a contrasting color. 

The frame and ring (hour hand) should be printed with support. The gears do not need additional support when printed separately. The Minute hand will print with the hand flat to the build plate. 
Make sure to print 2x Planet gears and 2x Planet Pins. 
Assembly is press-fit, but a drop of glue on the 2 ring pins and the sun gear should help . depending on your printer settings and tuning, you may want to reduce the “horizontal expansion” by 0.1mm or so and reprint.