Every few days I notice my laptop has lost maybe 30 minutes in time.

Is this likely to be indicating a bios/cmos battery on the way out?

Tis over 3 years old.

I suppose it is possible but I have a few boxes that are ten + years old and as far as I know they still have the original battery.

You could try and use hwclock to set the clock up. Use it to set the cmos(hardware clock) and then set the system time to the cmos clock. You can also use it to correct drift.

When do you notice the time loss? Is the time lost at boot or does it slowly lose it over the day?

What I know is that if the battery dies, the clock only works when the computer is on, that is, every time you do a new boot the clock resets.

Thanks all.

Time goes awry all of a sudden, probably at boot. Resetting it with the date format at the moment. Currently resetting it with the date command.

Hwclock seems a bit hairy!

Will see how things go and if it gets any worse.

as root will tell you what the bios clock is set at. Compare with the system and go from there. The system time will be set to the hardware clock at boot. If the hardware clock is wrong then so will the system time.

hwclock is showing the correct time. I'll wait until the displayed time goes squiffy and then check.

Ta.

Yesterday hwclock, desktop and real time were all in agreement.

Now it's about 6:30pm and hwclock and desktop are showing 17:57pm.

Any thoughts about where to go next?

Ta.

So your losing time while the system is up and running?

No, only between startups

Well now that does sound like a battery now.

It does but it doesn't happen everyt ime between startp.

Turned it on this morning and the time is as it should be. Grr.

I think I'll leave this and see how it goes. If it starts to cause a real problem then maybe I'll have a better idea of what the issue is.

Chris, idk how it is in a laptop, but in a desktop pc it's really easy to replace the battery and check. If the clock starts working fine again then that's it.