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Have a check of the output of timedatectl, considering with the meaning of each item, find out whether it’s logical regarding to the context as you know (configuration, connection,.etc.). if the item RTC time is n/a, one possibility is revpi-factory-reset has not be done correctly.
Have a check of the kern.log with dmesg, if there are rtc-pcf2127 error logs existed like following, it’s probably because the super cap is used out. Power on it, and let it be charged for a while (several hours) and reboot will be fine.
[ 10.528100] rtc-pcf2127 1-0051: pcf2127_set_datetime: err=-5
[ 10.528260] rtc-pcf2127 1-0051: pcf2127_get_datetime: read errorHave a check of the network connection to NTP server, whose URLs can be found in timesyncd.conf. Ping the NTP Server from device to see whether the network connection is available.
Have a look of the current time of the device, whether it’s 1970-xx-xx or 2016-xx-xx…. If it is in 2016, probably it is caused by discharge of RTC. and it is quite not common in Linux now that the time goes back to 1970.
Check the output of executing hwclock -w or timedatectl status to trigger the reading of the RTC, if it response message containing “Invalid argument”, it probably caused by reading the RTC failed, , which can be caused by one of two reasons:
a. Something happened with Oscillator in RTC, which you would see a warning log in kern.log as "oscillator stop detected, date/time is not reliable"
b. The time stored in RTC is not a valid time. e.g. earlier than 1970
Currently, no information about further determined reason for these problems, some analysis should be done according to use environment.Check the NTP time synchronization information with command systemctl status systemd-timesyncd
pi@RevPi1024:/etc $ systemctl status systemd-timesyncd
systemd-timesyncd.service - Network Time Synchronization
Loaded: loaded (/lib/systemd/system/systemd-timesyncd.service; enabled; vendor preset: enabled)
Drop-In: /lib/systemd/system/systemd-timesyncd.service.d
`-disable-with-time-daemon.conf
Active: inactive (dead) since Fri 2019-11-29 14:57:44 CET; 3 days ago
Docs: man:systemd-timesyncd.service(8)
Process: 2329 ExecStart=/lib/systemd/systemd-timesyncd (code=exited, status=0/SUCCESS)
Main PID: 2329 (code=exited, status=0/SUCCESS)
Status: "Idle."
Nov 03 18:17:38 RevPi1024 systemd[1]: Starting Network Time Synchronization...
Nov 03 18:17:38 RevPi1024 systemd-timesyncd[2329]: System clock time unset or jumped backwards, restoring from recorded timestamp: Fri 2019-11-29 14:51:23 CET
Nov 29 14:51:23 RevPi1024 systemd[1]: Started Network Time Synchronization.
Nov 29 14:53:15 RevPi1024 systemd-timesyncd[2329]: Synchronized to time server 217.91.44.17:123 (0.debian.pool.ntp.org).
Nov 29 14:57:43 RevPi1024 systemd[1]: Stopping Network Time Synchronization...
Nov 29 14:57:44 RevPi1024 systemd[1]: Stopped Network Time Synchronization.
Warning: systemd-timesyncd.service changed on disk. Run 'systemctl daemon-reload' to reload units.
References: