hwclock

The "hwclock" command line tool is used in Linux systems to interact with the system's hardware clock or real-time clock (RTC).

1. It is primarily used to read and set the system time from or to the hardware clock.
2. The hardware clock is a separate, battery-powered clock that continues to run even when the system is powered off.
3. The "hwclock" command can display the current system time stored in the hardware clock.
4. It can also set the system time based on the value stored in the hardware clock.
5. The tool allows specifying the hardware clock device to use if there are multiple clocks in the system.
6. It supports different time formats like UTC (Coordinated Universal Time) and local time.
7. The "hwclock" command can synchronize the system clock to the hardware clock.
8. It is often used during system startup to read the hardware clock and set the system time accordingly.
9. The tool can be utilized to adjust for time drift or discrepancies between the system clock and hardware clock.
10. The "hwclock" command can be executed with various options and arguments to perform different time-related operations.