Clock with 2 time zones

Hello.
Here is a clock that can display 2 time zones at the same time.
I made this clock because my wife is Chinese and wanted to be able to know the time in her country at any time.

2 buttons to adjust the local time as well as the offset for the 2nd time zone (GMT offset) as well as the brightness

This clock is based on an Arduino Micro (official). 2 LED Matrix (MAX7219 8x32) and a universal clock (RTC DS3231). These are easy to find and inexpensive modules.

To have a clean assembly, I decided to use a PCB that I designed and have printed via EasyEDA. I unfortunately cannot share the project directly on their site (my account is too recent), but I provide here the PCB, as well as the JSON which makes it possible to generate the project on EasyEDA. This site also allows to manufacture low cost PCB

You will also find the SketchUp file that I used to generate the 3D model of the different elements. As well as the INO file with the Arduino program.

I think that this asse