Place all nine two-sided pieces into the tray covering all months and days except leave the target date uncovered.
There are multiple solutions for each date of the year and it typically takes only a minute or two to find a solution for a specific date. Great during morning coffee for a daily solve that is not too difficult and not too easy.
Cherry laminate pieces and frame/border, birch ply tray bottom.
Measures ~4.6" square by 1/4" thick (117mm x 117mm x 6.4mm).
Shipping and handling: USA $5, Canada $11, Rest of the World $14.