Code: 
#!/usr/bin/env python
# -*- encoding: utf-8 -*-
import pygame, datetime
from copy import copy
from sys import exit

target = datetime.date(datetime.MINYEAR, 11, 7) # obscured for privacy
now = datetime.date.today()

if target.month == now.month and target.day == now.day:
  size = (800, 600)
  pygame.init()
  screen = pygame.display.set_mode(size)
  fps = pygame.time.Clock()
  pos = (0,0)
  direction = [3,2]
  font = pygame.font.SysFont('Helvetica', 48)
  s = font.render('Herzlichen Glückwunsch, mq!'.decode('utf8'), True, [255]*3)

  while 1:
    fps.tick(40)
    for event in pygame.event.get():
      if event.type == pygame.KEYDOWN and event.key in (pygame.K_f, pygame.K_ESCAPE) or event.type == pygame.QUIT:
        pygame.quit()
        exit(0)
    oldpos = copy(pos)
    pos = [pos[0]+direction[0], pos[1]+direction[1]]
    if pos[0] >= size[0]-s.get_width() or pos[0] <= 0:
      direction[0] = -direction[0]
    if pos[1] >= size[1]-s.get_height() or pos[1] <= 0:
      direction[1] = -direction[1]
    screen.fill([0]*3, (oldpos, s.get_size()))
    screen.blit(s, pos)
    pygame.display.update(([oldpos, s.get_size()], [pos, s.get_size()]))
Alles erdenklich Gute, mq.