4 ms·
The most precise for the hobbyist is probably a miniature atomic clock like https://www.sparkfun.com/products/14830 https://www.sparkfun.com/products/14830 "lo
by ranma42 5y ago
The most precise for the hobbyist is probably a miniature atomic clock like https://www.sparkfun.com/products/14830 https://www.sparkfun.com/products/14830
"loses a second every 4,000 years or so"