This is a simple design of a 24 hour digital clock, non-microcontroller, with selectable input voltages, 5, 9, and 12 volts, and has battery backup, which is not charging just providing backup power for brief power outages.

This is board only, you need to provide the parts and assemble. The design of just covering the 7-segment displays is to display the clock parts, to show what is making the clock work.

For schools/educators, this may be good introduction to soldering, and having the students learn the schematics as to how this is functioning.

Schematics and Parts List are listed below, and are needed to complete the assembly of the clock. I use component reference numbers, not values on the PCB.

The photo showing the completed clock shows the functioning clock without batteries installed. This PCB was manufactured through PCBWay and worked perfectly on assembly, zero rework needed, this is a quality board.

When soldering in X1, be careful as the holes are tightly spaced, just hold the iron to the outside, away from the second hole, when hot, a tiny dot of solder is perfect, then repeat on the other lead.