On Thu, Jan 02, 2020 at 04:55:32PM +0500, Mikhail Gavrilov wrote: > # hwclock -w -v > hwclock from util-linux 2.35-rc1-20-63f8 > System Time: 1577964536.796672 > Trying to open: /dev/rtc0 > Using the rtc interface to the clock. > Last drift adjustment done at 1577950892 seconds after 1969 > Last calibration done at 1577950892 seconds after 1969 > Hardware clock is on UTC time > Assuming hardware clock is kept in UTC time. > RTC type: 'rtc_cmos' > Using delay: 0.500000 seconds > missed it - 1577964536.797135 is too far past 1577964536.500000 > (0.297135 > 0.001000) > 1577964537.500000 is close enough to 1577964537.500000 (0.000000 < 0.002000) > Set RTC to 1577964537 (1577964536 + 1; refsystime = 1577964536.000000) > Setting Hardware Clock to 11:28:57 = 1577964537 seconds since 1969 > ioctl(RTC_SET_TIME) was successful. > Not adjusting drift factor because the --update-drift option was not used. > New /etc/adjtime data: > 0.000000 1577964536 0.000000 > 1577964536 > UTC At first glance it seems hwclock works as expected, I do not see anything wrong in the output. > Demonstration: https://youtu.be/Yx27IH2opEc What is hw time before reboot? Can you verify that hwclock reset the clock? (or is it system reboot?) # hwclock -w -v # hwclock -v Do you see anything interesting in dmesg output before reboot and after hwclock -w? (CC: to linux-rtc@xxxxxxxxxxxxxxx). Karel -- Karel Zak <kzak@xxxxxxxxxx> http://karelzak.blogspot.com