ChronoLog
Your Watch's Performance, Perfected
Ever wonder if your watch is running fast or slow? ChronoLog measures your timepiece's accuracy against atomic time, tracking performance patterns over weeks and months. Get insights into how your watches behave in different situations, spot potential issues before they become problems, and build the ultimate collection with precision data you can trust.
Have questions? Check out our FAQ.
Watch Accuracy Guides
How accurate should your watch be — and what can you do when it isn't? Practical answers to the questions collectors ask.
How accurate should a mechanical watch be?
Normal daily rates, certification standards, and when a service is due.
Measure your watch's accuracy at home
Three ways to get a trustworthy seconds-per-day number — no equipment needed.
Why is my watch running fast or slow?
Magnetism, service wear, or position effects — how to tell which one it is.
What is a timegrapher?
Rate, amplitude, and beat error readings explained, with healthy ranges.