This horizontal sundial works best at 45° latitude north, that is halfway between the North Pole and the Equator, where many cities are located.

You can check what countries the 45° parallel crosses here.

In order to make the sundial work, point the gnomon towards the true North on a sunny day.

(Here is how you can find the true north without Google maps or a compass).

The data used to build the sundial were calculated using this website.

The diameter of this sundial is just 3.7cm and it weights less than 8 grams of plastic. 

The sundial always gives you the winter time, not the daylight savings time.

The hours on the sundial are written in Roman numerals. In clockwise order you can read:

VI = 6 AM

VII= 7 AM

VIII= 8 AM

IX= 9 AM

X= 10 AM

XI= 11 AM

XII= 12 PM

I= 1 PM

II= 2 PM

III= 3 PM

IV= 4 PM

V= 5 PM

VI= 6 PM

Print with 0.1 layer height, preferably make a color change when the print is 3mm high from the base.