I had an idea about how to make a digital readout very easily for a timer project. It will not be challenging enough for the O/P, but I decided to post it for us mortals. Let's say the equation for pulse width is .693*R*C. So, use a 100K resistor and 144 uF capacitor ( not a typical value, use a 100uF and 47uF.... close enough) For the resistor, use a 100K, dual ganged, and connect the "other" resistor to 10V. Then, go to Harbor Freight Tools ( or some other Cinese product distributor ) and buy a cheap, $5 DMM. Wire the DMM to the wiper of the resistor you connected to 10V. Read out the timer value (seconds) in volts.
Edit: Changed my values.