Find offset between system-time and Internet time using Python

Question

How would you find the time offset between the local OS system-time and Internet time from various Internet time sources using Python?

score 6 · Accepted Answer · answered Jul 08 '11 at 08:32

6

Use ntplib. Right from the manual:

>>> import ntplib
>>> c = ntplib.NTPClient()
>>> response = c.request('europe.pool.ntp.org', version=3)
>>> response.offset
-0.143156766891

answered Jul 08 '11 at 08:32

phihag

278,196
72
453
469

This is an old question but what does the negative or positive offset mean? I am not sure which one is ahead, the PC time or time server time? – wondim Oct 30 '20 at 21:55
@wondim positive = remote NTP server is ahead. In the example in the answer itself, my local clock was slightly too fast. – phihag Oct 31 '20 at 11:17
Thank you! Mine was -4 so it is strange how it goes that ahead. – wondim Oct 31 '20 at 14:50

score 1 · Answer 2 · answered Jul 26 '11 at 22:09

Just to save you some time. Here's the code I ended up with using phihag's answer. It prints the drift every interval_sec to screen and to a log file.
You'll need to easy_install ntplib for it to work.

import logging
logging.basicConfig(filename='time_shift.txt',level=logging.DEBUG)

import ntplib
import time
import datetime
c = ntplib.NTPClient()

interval_sec = 60
while True:
    try:
        response = c.request('europe.pool.ntp.org', version=3)
        txt = '%s     %.3f' % (datetime.datetime.now().isoformat(), response.offset)
        print txt
        logging.info(txt)
    except:
        pass
    time.sleep(interval_sec)

Find offset between system-time and Internet time using Python

2 Answers2