A computer is turned on, and a message states the system time is incorrect.

The CompTIA Tech+ Study Guide (Exam FC0-U71, 3rd Edition, 2025) explains:

“Inside the BIOS, you can make system configuration selections such as changing the system time, selecting a preferred boot device, or enabling/disabling features.”

Additionally, it details:

“The CMOS chip must have power constantly or it will lose its information (just like RAM does when your computer is powered off). To prevent CMOS from losing its rather important information, motherboard manufacturers include a small battery called the CMOS battery to power the CMOS memory.”

If the system time resets or becomes incorrect after power off, it indicates a BIOS or CMOS battery issue. Configuring or replacing the BIOS/CMOS settings resolves it.

Verified Reference:

Chapter 1: Core Hardware Components — “BIOS and CMOS” (pp. 20–21).