The Anniversary Clock
One thing they don’t tell you about married life is that it’s measured on multiple time scales. Once you’re married, it’s no longer enough to remember what time of day it is. You also have to keep track of what time of year it is, lest you overlook the anniversary and end up paying for it for the rest of your life. But there’s another level up from that: the “Holy sh*t, I can’t believe how long we’ve been together” time scale. That’s what makes this clock special: it tracks all three.