Inspect and sync the hardware clock to prevent startup drift and keep logs consistent. 24.03.2026 | reading time: 2 min Is the system clock drifting after reboot or is log time inconsistent across machines Use the hwclock utility to read and manipulate the hardware real time clock and to copy time between RTC and system clock. Quick repair example A web server comes up with the wrong time Tell, do: first check the RTC with ```sudo hwclock --show``` which might output ```2026-03-24 10:15:00.123456+00:00``` then load the RTC into the kernel clock with ```sudo hwclock --hctosys``` and verify the system time with ```date``` which then shows the corrected time. Syncing directions you can use To persist a corrected system time into the RTC run ```sudo hwclock --systohc``` which writes the current system clock into the hardware clock; to set the RTC explicitly use ```sudo hwclock --set --date "2026-03-24 10:15:00" --rtc /dev/rtc0``` and to apply measured drift correction use ```sudo hwclock --adjust``` with a proper ```/etc/adjtime``` file. Options and pitfalls to watch Run hwclock as root and be aware of the RTC mode localtime versus UTC Many distributions and systemd's timedatectl prefer managing RTC timezone so check ```timedatectl``` before changing hwclock; also avoid clashes with active NTP services which will fight manual changes. Tools that work with hwclock Use hwclock alongside system utilities that manage time and synchronization For example consult `timedatectl` for systemd machines and pair hwclock use with `chronyd` or `ntpd` when maintaining consistent time across a fleet. Takeaway and next steps hwclock is a small but powerful tool to inspect and align the RTC with the system clock Practice the commands in a safe test environment and then consider studying deeper system administration topics and certifications at bitsandbytes.academy to master Linux time management. Join Bits & Bytes Academy First class LINUX exam preparation. utilities boot-process troubleshooting
