What would cause a digital clock to lose time?

Chevy truck, clock is part of the radio.  If I pull the fuse even for a split second the radio stations in memory disappear.  Lately I get in and the clock is 15 - 50 minutes slow.  If it lost power all the stations would be gone.

Experiences?

Dan

In for answer.  Digital clock in my car loses about 10 minutes in 6 months, so when I reset for the time change, I set it to +5min over real time.

My wife's fairly new digital alarm clock gains time pretty rapidly. To the tune of maybe 8 minutes a month. However my Black&Decker digital alarm clock from 1988 or so is always spot on.

processor for the clock is failing, unable to keep time.

Replace it or ignore it.

Have you orbited the earth or taken any trips to space recently?

Easy fix. First remove the flux capacitor. Second stop driving 88 mph. 

Mine too.

I replaced the head unit, and it keeps the time differently, but also incorrectly.

Weird, right?

Huckleberry said:

Have you orbited the earth or taken any trips to space recently?

Well yeah, but I didn't take the truck.

Thanks guys.  I'll ignore it for a while, unfortunately there's no replacement for the big square factory GM radio.

My GM radio loses about a minute a month. It has since it was brand new. I have come to accept that maybe electronics aren't quite as precise as I was led to believe. 

Replaced the headunit in the wife's truck years ago. It actually gains time. Usually about 4-5 minutes per month. Once it gets to be half an hour off I change it. 

914Driver said:

Huckleberry said:

Have you orbited the earth or taken any trips to space recently?

Well yeah, but I didn't take the truck.

Thanks guys.  I'll ignore it for a while, unfortunately there's no replacement for the big square factory GM radio.

You mean that goofy shallow 1.5 DIN?

https://www.retromanufacturing.com/products/1990-95-gmc-safari-newport-1-5-din-direct-fit-radio?variant=31557244046

In reply to 914Driver :

there's lots of options. We chose the extra cubby option under a DIN radio. that's where my cell phone sits.

IIRC, digital clocks maintain their time from the hertz oscillation rate of their power supply or a quartz crystal, excited by an electrical supply with a known oscillation rate.  The point being that if your electrical supply's rate of oscillation is changed, the clock will speed up or slow down.  This is how people break into time-release locks on bank vaults, though you didn't hear that from me.  

I suppose something similar could be happening in the truck with worn out components?  

I have an atomic clock that is 7 minutes off no matter what I do.  Explain that one.  

There is a quartz crystal that is actually keeping time.  The crystal will change frequency with temperatures.  To correct for that, there are additional circuits applied.  Either these additional circuits are not tuned properly, not designed properly, or failing/changing values.  Live with it or replace it.  

1995 Chevrolet Lumina.  Swap out the battery which involves removing a lot of crap.   Clock in radio glows bright and wears down new battery overnight.  Pull the fuse for the radio memory and clock and have to dial in the stations every time.

16 year old son doesn't understand why we can't fix it.   Because it's a GM product.  Then one day we sold the car!

Time isn't holding up.

Time isn't absolute.

Same as it ever was.

pinchvalve said:

IIRC, digital clocks maintain their time from the hertz oscillation rate of their power supply or a quartz crystal, excited by an electrical supply with a known oscillation rate.  The point being that if your electrical supply's rate of oscillation is changed, the clock will speed up or slow down.  This is how people break into time-release locks on bank vaults, though you didn't hear that from me.  

 

Uhhh...yeah... that's what I was going to say...sorta, kinda...

My GMC truck has the same clock-gaining-time issue. On Friday it 10 minutes fast. On Sunday the time was exactly right; then I remembered I had rest the clock after disconnecting the battery on Saturday.

Maybe it's not just a crystal that's losing a bit of performance.

it's just a jump to the left...

I had a Focus that would gain 9 minutes after it was reset. It took about a week and once it was 9 minutes fast it would stay that way for months.