Which utility accesses the hardware clock, independent of the OS?

The utility that accesses the hardware clock, independent of the operating system, is hwclock. This command directly interacts with the hardware clock (also known as the Real-Time Clock or RTC), which is a small battery-powered clock that keeps track of the current time even when the computer is powered off.

Using hwclock, you can view the current time stored in the hardware clock, set it, or synchronize it with the system clock. This capability is essential for ensuring that the system time is accurate, especially during boot-up or when the system is powered down for extended periods, as the hardware clock continues to run independently of the OS.

The other options tend to interact with the system clock or manage time settings within the operating system instead of directly accessing the hardware clock. For instance, date is primarily used for displaying or setting the system time, while timedatectl manages the system time, timezone, and NTP synchronization. localectl deals with system locale settings and does not directly interface with the hardware clock at all.