Create a Y2K disaster Your program can do anything you want. The only condition is that it perform as expected if the date is before 2000, and fails spectacularly afterward. Define spectacularly however you'd like.

For all those people who missed the first Y2K, here's your chance!

Answer with highest score wins.
Python

Real Y2K bugs are about the year being represented as a 2-digit number. And doing something wrong when that number overflows to 0. Such as this nuclear missile watchdog, launching all ICBMs if we haven't received a heartbeat message from HQ in 60 seconds.

import datetime, select, socket, sys

launch_icbm = lambda: (print("The only winning move is not to play"), sys.exit(11))
now  = lambda: int(datetime.datetime.now().strftime("%y%m%d%H%M%S"))
sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
sock.bind(('0.0.0.0', 1957))
last_message_received = now()

while True:
    r, w, e = select.select([sock], [], [], 10)
    if sock in r:
        msg = sock.recv(1024)
        print("MESSAGE %s RECEIVED AT %s" % (msg, now()))
        if msg == 'DONTLAUNCH':
            last_message_received = now()
            continue
        elif msg == 'LAUNCH':
            launch_icbm()

    # Is HQ dead?
    abs(now() - last_message_received) &gt; 60 and launch_icbm()