That's hilarious. I take it vampires are immortal, because that days remaining number is mathematically significant: It's the value that you arrive at with a signed 32 byte integer at its maximum positive value then add 1. The number overflows from 31 1's to a single 1 followed by 31 0's, which computers interpret as -2147483648
Assuming for a moment that when that day timer ticks down, it'll loop back up to the highest 32-byte signed integer (2147483647), and assuming that you leave the game running, lag-free and with no interruptions, it will take slightly less than 100,000 years for the vampire's mid-life crisis to end. (Of course I don't know the game mechanics, I'm simply assuming that the days remaining ticks down to 0 then the crisis ends)