The presumption that something digital keeps time better over something analog is a false one. Poorly designed is poorly designed. I have $3000 NTP clocks at work that drift terribly when they can't sync up to an outside source. The clock in my car is off by 7 minutes right now because it runs fast. I can reset it an it will be off like this again in just a few months. A precision gear\spring clock can keep time for years with less drift.
NIST testing on wristwatches shows that crystal oscillator watches can be expected to keep time accurate to approximately 1 second per month.
The best, chronometer certified, mechanical watches have an accuracy of ~25-30 seconds per month.
If you've got digital clocks that are off by that much - they're probably not using crystal oscillators, or the power source for them is really poorly regulated.