Here is the measurements for the design I used.
Step 1: Wood
Select a few pieces of wood to use.
Step 2: A Square Makes a Circle
After planing the wood to desire thickness, cut the strips of wood to about an inch longer than the diameter of the circle. Then glue them side by side to make a square.
Step 3: Cut It Out
After the glue dries, cut out a circle.
Step 4: Do Some Sanding
Sand the wood until it is smooth.
Step 5: More Cutting
Cut out the diamonds and circles to be placed as time markers.
Step 6: Mathematics?
Use a protractor to measure the angles for the pieces. They should be placed at 30 degree intervals.
Step 7: Check It Over
Double check your pieces and then glue them in.
Step 8: Polyurethane
After sanding the pieces and clock apply coats of polyurethane while using steel wool between each coat.
Step 9: Telling Time
Place the numbers "12-3-6-9" on the four circles. Instead of putting the other numbers on just use the diamonds as the placeholders.