The calendar complication is one of the more commonly seen complications in mechanical wristwatches. One thing they don’t do is keep track of leap years where an extra day is added to February. To correctly show February’s leap day, you would need a perpetual calendar complication in your watch, which is comparatively much more complicated, and much more expensive than a normal calendar complication. Beyond leap days and years, there are leap seconds. Leap seconds are applied to coordinated universal time on an occasional basis, to account for a small irregularity in the Earth’s orbit. What if you wanted to take the accuracy of your watch one step further, and keep track of leap seconds? Then you definitely need a Hoptroff watch.