Tkinter Time Button

#!/usr/bin/python
#
import Tkinter as tk
import subprocess
import datetime
import time
import sys

def getButton():
    utc_time_on_your_pc = datetime.datetime.utcnow().replace(microsecond=0)
    timer = datetime.datetime(2013, 5, 30, 14, 0, 0) - utc_time_on_your_pc
    if timer < datetime.timedelta(0):
        timer = datetime.datetime(2013, 6, 4, 2, 0, 0) - utc_time_on_your_pc
    return ": : :  "+str(timer)+"  : : :"

def task():
    """
    This is a wrapper to repeatedly run another function
    """
    button["text"] = getButton()
    root.after(500, task)


def quit():
    """
    When the button is pressed this will exit to system
    """
    global root
    root.quit()
    sys.exit(0)

if __name__ == '__main__':
    root = tk.Tk()
    while 1:
        button = tk.Button(root, text=getButton(), command=quit)
        button.pack()
        root.after(2000, task)
        root.mainloop()