What would you use to build a precision timekeeping device (no radio or atomic clocks)?

Question

What would you use to build a precision timekeeping device (no radio or atomic clocks)?

Answer 1

Here are some clock kits:

http://electronicsusa.com/ck1k.html

http://www.techkits.com/

http://www.hobbytron.com/ClockKits.html

There are probably some free schematics for clocks out there on the internet too if you are an experienced kit builder.