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The who -b command desn't show me the last reboot times on my Raspberry 3

    :~ $ uname -a
Linux xxxxx 4.9.35-v7+ #1014 SMP Fri Jun 30 14:47:43 BST 2017 armv7l GNU/Linux
:~ $ who -b 
    system boot  1970-01-01 01:00

I configured the ntp daemon as the date is uptodate.

How to configure the system for getting this king of information.

Regards,

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2
  • "who -b" should work. "last reboot" is also borked This is a bug
    – Max Robbertze
    Commented Nov 16, 2020 at 14:09
  • Does journalctl --list-boots help?
    – Pablo A
    Commented Nov 12 at 0:58

1 Answer 1

Reset to default
8

Short answer: Use: uptime --since (-s for short)

You can use the uptime command to find out how long it has been since the Pi (or any Unix/Linux OS) has booted. The -s flag tells uptime to calculate the boot time.

The Pi doesn't have a real-time clock (though there are RTC chips that you can add). This means it does not know the date/time as it boots. If it has access to a network, it'll reach out to a time-server to set these. But if it doesn't have a network, it will rely on a fake hardware clock (basically a file where it periodically writes the time). It isn't accurate, but at least it fixes problems where log files have "newer" entries with older date/time stamps than "older" entries.

See also.

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