Tuesday, March 18, 2008

Apple OSX - time does not get set automatically

Even though my laptop is on 3 or 4 hours a day, every day, I noticed that the time was still wrong by over 3 minutes. What gives?

The frequency that the NTP daemon checks is set in

/etc/ntp.conf

and the default are

server time.euro.apple.com minpoll 12 maxpoll 17

Also, OSX should work out how much the time drift and puts it in /private/var/run/ntp.drift but on my system this file has the value '0.000' which means OSX thinks there is no drift.

This means that with zero drift OSX will check the time every 2^17 = 131,072 seconds or ~36 hours. Even with some drift it will only check every 2^12 = 4096 seconds or about 1.5 hours.

So my quick solution is to change /etc/ntp.conf to

server time.euro.apple.com minpoll 6 maxpoll 12

which increases the frequency of time checks.

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