If I completely shut down a computer and not use it for months, how can it still tell the time accurately? (given that it isn’t immediately connected to the internet)
In: Technology
There’s a watch battery (usually a CR2032) on the mainboard of almost all modern computers that keeps the clock circuit ticking over, just like in your digital watch (which uses the same kind of battery and can go years, especially if it doesn’t have to display the time at all). Even things like satellite TV boxes have them in, for the same reason. They didn’t use to, but for decades now the chips are standard and there’s likely a CR2032 sitting (maybe upright) in that box keeping the time.
To be honest, the only mass-market device I know that doesn’t have an RTC is the Raspberry Pi / Arduino, and both have “hats” you can buy to add one on. Those hats use… a CR2032 battery and the same chip as everyone else.
But in the modern day, it barely matters because you don’t need an accurate time for most things, the thing you really need an accurate time for is things like checking secure certificates on websites, and by the time you’re there, you’re already online and likely picked up an incredibly accurate time from an NTP server on the Internet (usually time.windows.com or pool.ntp.org).
The only thing I know that demands a correct time, albeit quite inaccurate, is logging onto a Windows domain computer (where the time has to be within about 5 minutes of the server). But, again, one of the first things that computer will do is talk to the domain controllers and try to pick up a time from them.
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