Clock running fast

Thanks I'll try that and see if it works.

Well, I have now found that having the location setting unchecked makes no difference. The clock still gains a few seconds per hour.

Second, simply opening the System Prefs / Date & Time pane corrects the time. I don't need to uncheck and recheck the time server box.

Now, I'm going to try trashing the prefs.

Well, no, trashing preferences has not helped. Already after about half an hour I can see a one second advance on this clock.

I'm worried that the wrong time may affect many other applications such as Mail, Dropbox and a live trading app I use in Citrix, where seconds really count, let alone minutes.

I'm surprised, however, that no-one else has reported this. Could it be no-one has noticed?

Some keywords to ease searching: iMac clock shows wrong time; Mavericks clock wrong, Apple time sync not working.

Now I have reset the PRAM, and the iMac clock is still running fast. I can't think what else I can try.

It seems to me this must be a Mavericks problem because the computer was definitely working fine before Mavericks - I check pretty much every day because there are certain markets that open at specific times.

And yet no-one else seems to have reported this problem, so I really don't know what to think. I'll see if I can get this fixed under the warranty.

Hey thanks for drawing my attention to that other thread. I'm going to try rebooting in Safe mode, failing that Recovery mode (if it exists on an iMac) and failing that I'll try a different time server, but I don't think the latter will be the problem as I've tried a few already. It's still driving me nuts! Will report back.

OK Drew, I can confirm that booting in Safe Mode http://support.apple.com/kb/HT1564?viewlocale=en_US fixes the problem, at least as long as I stay in Safe Mode. I.e. the clock keeps perfect time.

I have now rebooted in normal mode and will monitor to see if the problem has been fixed permanently.

As an aside, in Safe Mode, Mail, message centre, Finder all behave weirdly. The message centre actually displayed text 180 degrees inverted in the vertical plane - like a mirror image ! I couldn't take a screen shot though, it would disappear when I tried to do this. I saw this behaviour somewhere else several years ago on my old computer in a different place - I think the Get Info window. It fixed itself after a few months.

Also, in Safe Mode, before actually logging in (but after rebooting), the clock is still wrong, but this time, strangely, it is slow, not fast. As soon as I log in the clock corrects and stays correct.

In fact, just logging in after a normal restart is also enough to set the clock correctly, but then it would start to gain time.

Anyway, will monitor and report back if my problem is now permanently fixed or not.

Yesss! It looks like the reboot in Safe Mode solved the problem. Many thanks for your help Drew - I don't know how I would have solved it without your post.

It's actually fixed permanently 🙂 I'm now back in normal mode and it's keeping time perfectly. So exactly the same problem and solution as fredbourgouis in the thread you linked to: https://discussions.apple.com/thread/5545153?answerId=23745999022#23745999022