From the moment a person is born, the hourglass is turned. Fate put in motion. Every person has until the last grain of sand falls to find their soulmate.
And no, it's not a "countdown to the moment they meet their soul mate" it's a "during this time you should have met your soul mate, if you haven't figured it out by now your bond is severed" kind of countdown.
If they don't, they are doomed to a lifetime of loneliness.
I only have 22 hours left.

***

"But if you try tampering with it you could die!"
"I would rather die trying than live a lifetime of loneliness"