I have a sketch "Arduino Matrix Clock" which, as the name implies, is a clock with 4 LED Matrix + DS3231 + 2 Buttons.
As I understand (correct me if I'm wrong), to enter adjustment mode, keep pressing both buttons simultaneously, then press one button to increment and the other to set.
Dancopy:
to set the clock, I would press, for example, the OK key on the control, then to adjust the hour and minutes, I would press the number keys
Define what this means. To set minutes, say, will the time increment as before only now the '2' key is pressed repeatedly? Or, to set minutes at 43 will the '4' key and '3' key be pressed? How will the switch from hours to minutes look?
It'd probably be a good idea to familiarize yourself with the IRremote library.