Two computers and an iPhone - all display different times

[asante]

I have an iMac and a MacBook Air, both running OS X Yosemite 10.10. Both set the time zone, date and time automatically. I noticed recently that they display slightly different times. When I checked, the iMac showed 14.43.14 while the MacBook said 14.42.34. www.timanddate.com said it was 14.38.30. I looked at my iPhone 5 (iOS 8.1.2) which told me the time was a full five minutes earlier than the MacBook. All devices are running on the same wifi network. I have tried all of the obvious things like re-starting, checking that location services are on, but no luck. I tried to find the invisible folder etc/localtime, but could not find it, so if that is involved please let me know where it is hidden. Any advice would gratefully received.

 

[Lifeisabeach]

I have an iMac and a MacBook Air, both running OS X Yosemite 10.10. Both set the time zone, date and time automatically. I noticed recently that they display slightly different times. When I checked, the iMac showed 14.43.14 while the MacBook said 14.42.34. timanddate.com said it was 14.38.30. I looked at my iPhone 5 (iOS 8.1.2) which told me the time was a full five minutes earlier than the MacBook. All devices are running on the same wifi network. I have tried all of the obvious things like re-starting, checking that location services are on, but no luck. I tried to find the invisible folder etc/localtime, but could not find it, so if that is involved please let me know where it is hidden. Any advice would gratefully received.

Hmmm. That's an interesting problem. I just did some digging and I may have found what the problem may be. Check out this discussion on Ask Different:
Clock won't keep time after Mavericks installation - Ask Different

In this case, the problem was a corrupted file from doing a Mavericks upgrade. According to these guys, the people seeing the problem did an "upgrade" installation while those who aren't seeing it did a clean install. This discussion was about Mavericks, but the problem may have followed Yosemite.

One solution posted was as follows:

1. Replace Mavericks' buggy usr/sbin/ntpd executable with the one from your backups or other Mac with the previous version of OS X.
2. Delete var/db/ntp.drift
3. Restart the ntpd process using the new executable

 

[MacInWin]

Is that ntpd the file Apple just updated because of a security risk? I would be somewhat reluctant to revert if that was the case.

 

[Lifeisabeach]

Is that ntpd the file Apple just updated because of a security risk? I would be somewhat reluctant to revert if that was the case.

I wouldn't necessarily revert to an older version. I would install a clean copy of Yosemite to an external drive or unused partition, then fully update it. Once done, copy the file off that clean installation.
Alternatively, get a copy of the file from someone with a fully updated installation of Yosemite who isn't having this problem.

This is all assuming that the solution posted was indeed what the problem is here. We don't know this for sure yet.

 

[Lifeisabeach]

Back to asante, I forgot to ask... do you have all the current updates installed for Yosemite?

 

[asante]

Hmmm. That's an interesting problem. I just did some digging and I may have found what the problem may be. Check out this discussion on Ask Different:
Clock won't keep time after Mavericks installation - Ask Different

In this case, the problem was a corrupted file from doing a Mavericks upgrade. According to these guys, the people seeing the problem did an "upgrade" installation while those who aren't seeing it did a clean install. This discussion was about Mavericks, but the problem may have followed Yosemite.

One solution posted was as follows:

Thanks, Lifeisabeach. The difference between the discussion you linked me to and my case is that in my case clicking Date and Time does not reset the clock. I'll follow your advice up tomorrow and see where It takes me.

 

[asante]

I wouldn't necessarily revert to an older version. I would install a clean copy of Yosemite to an external drive or unused partition, then fully update it. Once done, copy the file off that clean installation.
Alternatively, get a copy of the file from someone with a fully updated installation of Yosemite who isn't having this problem.

This is all assuming that the solution posted was indeed what the problem is here. We don't know this for sure yet.

Thanks again Lifeisabeach and thanks for the warning MacInWin. I guess at the end of the day the question will be whether it will be worth the hassle of re-installing on several devices just to get the time perfect. I haven't had the strength to check what the discrepancy is against my MacBook Pro and my wife's computers!

 

[Lifeisabeach]

I just noticed that I don't even have the security update installed yet that MacInWin referred to. I thought I had read that Apple pushed it out automatically. In fact, I did read that, but apparently they didn't do that.
Apple pushes first ever automated security update to Mac users | Reuters

Make sure you have no updates pending in the App Store for Yosemite. If not, then manually download that security update and apply it. Maybe that will iron out any bugs.
https://support.apple.com/kb/DL1782?viewlocale=en_US&locale=en_US

 

[asante]

So, now I have updated Yosemite to 10.10.1 and just for safety manually installed the security update. (I too had not seen the push notification for the update). Nothing has changed, and the computer I did this to is still happily showing the wrong time. However, in all of this investigation, I have confirmed that all of my iOS devices show the same time, and they are pretty-well identical to internet time sites. So, as I have a correct reference to the right time, I will now spend some time getting the security update on all of my computers and decide to live for a while with aberrant OSX machines. I think it is time for me to get this to Apple and ask them to add this to their list of needed fixes. My thanks to Lifeisabeach and MacINWin for your help, which has been very helpful. I have at least covered a security risk.

 

[Lifeisabeach]

If you haven't tried resetting the PRAM, do so. That stores a bunch of settings, including some for the date/time.
https://support.apple.com/en-us/HT204063

 

[asante]

Thanks again Lifeisabeach. Re-setting the PRAM was one of the first things I did, and I have just done it again, with no change. The pointer you gave me earlier towards getting the ntp file from a clean install is something I will try when I have time or can find a clean installation on another computer