Hope you’ve been taking care of yourself. The A. Lange & Söhne 1815 Rattrapante Perpetual Calendar ($189,000 in rose gold, $213,000 in platinum) won’t need to be corrected until the year 2100 (only one in four century years is a leap year — 2100 is not). That’s 87 years of being entirely correct; not even your better half can beat that.

Two of the most popular complications in horology today are the rattrapante, or split seconds, chronograph and the perpetual calendar. The Lange 1815 combines them. If that didn’t already make it the coolest of the cool, it throws in a pair of additional complications to boot: a power reserve function and moon phase. The lunar display goes even longer than the calendar, only needing correction by a day every 122 years. Better leave instructions for your heirs.

In case you’re new to the rattrapante complication, this unique addition to the chronograph function allows the timing of two related events, say, determining the split times between Hunt and Lauda or Kanaan and Castroneves, tracking lap times along with cumulative race time, etc.

That’s a lot going on under the hood, yet Lange has kept the watch relatively petite. The 41.9mm diameter by 14.7mm thick case houses 631 parts total, 211 of them dedicated to the perpetual calendar alone. Finally, when you’re wrapping up this much complication, it doesn’t make sense to do it in less than gold or platinum — your choice, of course. We break it all down for you above.