computer time

jone kim · 04-26-2010, 02:23 PM

I want to know how the computer sets time? When I turn off my computer or it is not connected to internet it shows me the correct time. When I login to my computer after so many days, it shows me the correct time though it was turned off for so many days. How is it possible?

Please explain this to me.

catkin · 04-26-2010, 02:26 PM

It has a battery-powered clock.

EricTRA · 04-26-2010, 02:26 PM

Hi,

There's a small battery on your motherboard that feeds the BIOS with power so it can remember the time when powered off or even disconnected from the power outlet. If you take out the battery, your computer will forget all about time and date.

Kind regards,

Eric

kirukan · 04-26-2010, 02:29 PM

There is a battery that battery give current to CMOS, CMOS maintain the date and time. Hope this is you are asking

MTK358 · 04-26-2010, 03:19 PM

The motherboard has a 3-volt coin cell battery in it to power the clock.

Shown around the lop-left corner in this image:

http://en.wikipedia.org/wiki/File:Asus_a8n_VMCSM02.jpg

michaelk · 04-26-2010, 03:57 PM

In a nutshell to sum it all up...
The typical PC compatible computer contains a hardware real time clock chip that maintains the current time when the computer is off via the CMOS battery. During the boot process the OS reads the hardware clock and sets the system clock to the same time.

Lots of info on the topic can be found on the web.