Hi Steve,

100 years ago they use to get 2 seconds a month accuracy with jeweled wind up clocks. During the 60's Bolova with their Accutron watches advertised 2 seconds accuracy per month. I would think we have come a long way since these two examples, but we haven't. Crystals will give you .002% accuracy right out of the box but with another step we could get 1000 times more accuracy but it requires spending another dollar per unit.

Thank you,

Charles Bannister