The Habit Tracker PCB can be ordered from @oshpark or PCBWay  (@Anson)

https://oshpark.com/shared_projects/VAJZCRZ8

https://www.pcbway.com/project/shareproject/W102531ASU6_MotivationalBoardV1Prod.html

This jig  by will help you install the switches in alignment.

https://www.thingiverse.com/thing:3018815

This circuit is very forgiving. It's only an LED, and current limiting resistor in series with an inordinate amount of switches. The LEDs for different months do not have to be the same color. Experiment in a protoboard with the desired or available LED and current limiting resistors to ensure they will work. If no protoboard is available, solder the switches for a whole month first and then hold the resistor and the LED by hand. 

I ended up using 9V, 4.7K and Blue LEDs because I had that on hand. 

Insert all the switches in a month and use the 3D printed alignment jig to hold them in place. Flip the board and solder them

If you have not decided on a current limiting resistor and LED color, this is the time. Solder the master power switch (below and to the left of the January column). Solder the power leads for the voltage source available and experiment with resistor sizes and LEDs. 

Do not solder the LED at this time, wait until all columns have been soldered.

Repeat steps 4 and 5 until all 12 months have switches and current limiting resistors soldered.

Power the circuit and flip all the switches in a month to the left (on position). Flip the master power switch to the left also. Insert an LED at the end of the column and verify it light up. If it does not, flip it. If it still does not illuminate, check your work. Verify the batteries are not dead, measure power to each switch leg going up the month column. 

Once the LED has been tested to work, solder it. 

Repeat for all 12 months.

The PCB has 2.5mm standoff holes in the corner. Insert some standoffs there.

Decide on a habit to track and flip a switch to the left for each day the goal selected is met. If starting at the middle of the month, flip all the switches before today to the left. 

Decide on a protocol for making up missed days. This will ensure the board is useful even if a day or two are missed.