We all know what it's like to wake up in the middle of the night and wonder what time it is and is everything ok.
But once you check your phone, you're wide awake.
Mark Zuckerberg's wife was waking up, wondering if it's time for the kids to be waking up... and stressing out about it.
So he built her this sleep box, which lets her know (through a soft light) when it's between 6am and 7am.... otherwise, it's dark, so she knows to roll over and go back to sleep.
As Mark put it, "As an engineer, building a device to help my partner sleep better is one of the best ways I can think of to express my love and gratitude. A bunch of my friends have told me they'd want something like this, so I'm putting this out there in case another entrepreneur wants to run with this and build sleep boxes for more people!"
Now we all want a sleep box. And a husband like Mark.