I don't know much about pics but i have built an electromechanical tacho generator which generates my alternating 1 second impulses to drive my T&N and CT Wagner and FAVAG one second slave clocks.
The principle i used is similar, timewise, as used at the German railways by T&N so called "Schleichenden Sekunden".
I run an ac synchronous motor with a geartrain generating 60 impulses in 58.6 seconds.
The impulses are picked up from a small disc with black marks sensed via two opto sensors (used in kWh meters to read a black mark from a disc in a meter.)
These give me the alternate impulses.
Via an electronic driver i amplify these to 24 volts / 2 ampères to be able to drive many slave clocks.
A cam will open a micro switch, the motor stops, and waits for the next minute impulse from the master via a 24 volt relay, which overrides the microswitch and the process stops again.
It looks quite good, the seconds hand click happily away up to the 12, waits just over one second, the minute hand advances, then the second hand starts moving again.
There may be easier ways to accomplish this, but electronics and electric clocks are a hobby of mine, so time is not an issue and i fiddle around with these projects when the kids are asleep and my wife visits her forums on the internet.