Script to update datetime when its not possible to connect to NTP servers

update_datetime.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-


import urllib2
import sys
from datetime import datetime, timedelta
import os
import time


def update_local_time():
  # Get datetime
  dt = urllib2.urlopen("http://www.google.com").headers.dict["date"]
  print dt
  dt = datetime.strptime(dt, "%a, %d %b %Y %H:%M:%S %Z")

  # Set UTC time
  print "Setting UTC time to {}".format(dt)
  txt = dt.strftime("%m%d%H%M%y")
  r = os.system("date " + txt)

  # Guess UTC offset
  is_dst = time.daylight and time.localtime().tm_isdst > 0
  utc_offset = - (time.altzone if is_dst else time.timezone)
  if utc_offset:
    dt += timedelta(seconds=utc_offset)
    # Set Local time
    print "Setting Local time to {}".format(dt)
    txt = dt.strftime("%m%d%H%M%y")
    r = os.system("date " + txt)

  return r


def check_root():
  return os.getuid() == 0


if __name__ == "__main__":
  if check_root():
    r = update_local_time()
  else:
    print "To run this script you need admin rights"
    r = 1
  sys.exit(r)