How do computers always know what the correct time is?

Question

I've been wondering, how do computers, regardless of how long they're turned off, always know the correct time?

Answer 1

A battery holds up the CMOS clock and memory circuits on your motherboard. If you unplugged your computer and set it in the corner for a few years, the battery would go dead, and the clock would be WAY OFF.

But Windows XP's time of day clock depends on the proper Time Zone setting, and an occasional internet connection to look up the correct time, and correct the time. Previous systems might eventually wander off.

Good luck and Happy Computing!

Answer 2

All computers, whether they are desktops or laptops, have tiny watch batteries on their motherboards. This battery keeps alive certain areas of memory, including the clock. This is why the computer can always keep track of time, even if its unplugged.

On top of that, all modern computers with an Internet connection actually go online periodically and synchronize their clocks with the Atomic Clock in Colorado, which is considered the "official time" for the USA.

Answer 3

PCs have an internal clock, kept alive with the little bios battery, and looks like a watch battery. When you say correct, I have to laugh as most PCs lose a few minutes every month. I finally synched my PC to an atomic clock, software available free on the net.

Answer 4

computers have a small battery on the mainboard that keeps the clock running. The tiny current draw means the batteries will last for years without failing

Answer 5

I think, even when they're turned off, there's a battery inside that keeps essential things going, the clock among others

Answer 6

computers know the correct time because u have 2 set the time

Answer 7

Computers have a separate battery to keep track of time. It looks somewhat like battery that comes out of a watch, but bigger.
If that battery goes, you will not have the right time

Answer 8

There is a battery on the motherboard inside the tower (like a watch battery) that keeps the time.

Answer 9

CMOS (backup) battery. Keeps BIOS going even when the computer is turned off. All it has to do is count seconds/minutes/hours etc. Similar to how a graphing calculator remembers everything even after you turn the calculator off.

Answer 10

they probably get the time from the net or they have a internal clock that can get charged when you turn on your computer.