Keeping Track of Time

A computer system has a different concept of time than us humans. For a computer system, time represents a passage of time from an arbitrary starting point. More precisely it is the number of seconds elapsed from January 1st, 1970 UTC. This is referred to as System time.

These systems also have a battery-powered hardware clock that keeps track of time the way humans do. This clock hardware clock sometimes referred to as Real-time Clock (RTC), or the CMOS clock.

Linux system time#

Linux assumes that the hardware clock is in UTC and applies an offset to it for the local timezone. This is fine if linux is the only operating system installed.

Windows time#

Windows assumes that the hardware clock is already in local time, so if the RTC is set to UTC, windows will display the wrong time.

The Fix#

Make Linux use local time. From the terminal run use timedatectl to adjust the system clock

timedatectl set-local-rtc 1 --adjust-system-clock