import threading
def waiter():
    e = threading.Event()
    print("wait 10 seconds")
    e.wait(10.0)
import os
import time
from datetime import datetime, timedelta
def sync_time():
    t1 = threading.Thread(target=waiter)
    t1.start()
    time.sleep(1)
    os.system("/usr/bin/timedatectl set-ntp 0")
    date = (datetime.today() - timedelta(days=1)).strftime("%d %b %Y %H:%M:%S")
    os.system("/bin/date -s \"" + date +"\"")
    t1.join()

if __name__ == "__main__":
    sync_time()