I want to know the uptime since the last wake from standby.

The command uptime only shows the difference between current time minus the last startup time.

11 Answers 11


In /var/log/pm-suspend.log, look for the last line looking like this one:

Sun Dec 16 09:30:31 CET 2012: Awake.

That's your last wakeup time. You can calculate your uptime since then the way Paul suggested.

Periodically your logrotate will "rotate" logs to prevent them from growing too big, so you may find an empty pm-suspend.log file. In this case, just look for the pm-suspend.log.1 file (you may find also other log files named like pm-suspend.log.2.gz and so on; you can examine them using zcat or zless).

  • this worked for me – Prozi Jun 26 '14 at 15:58
  • 5
    What if pm-suspend.log is empty? :( – cprn Oct 27 '15 at 12:50
  • 1
    If you also care about suspend timestamp, use: cat /var/log/pm-suspend.log /var/log/pm-suspend.log.1 | grep -B1 Awake; echo "--"; zcat /var/log/pm-suspend.log.*.gz | grep -B1 Awake – webbertiger Nov 5 '16 at 0:33
  • 2
    No such file in my computer (running Ubuntu 16.04 LTS) – Ramon Suarez Oct 1 '17 at 13:46
  • File is present only if you installed the pm-suspend. But for example Kubuntu goes to suspended state also after I close the notebook. Then the pm-suspend file is empty. – dmatej Oct 3 '17 at 11:51

For desktops/servers running systemd, while there is no direct command that will tell the info directly (as far as I am aware), all the data is captured in the journal.

You can grep the journal, for example:

echo ">> [SUSPEND] Times during current boot"
journalctl -b 0 |grep "]: Suspending system..."
echo ">> [WAKE] Times during current boot"
journalctl -b 0 |grep "PM: Finishing wakeup"

Or, for fancy output, I wrote a python3 script (runs fine on Fedora 23) Sample output:

Initial Boot Timestamp:  2016-01-15 09:31:32 

     Wake Timestamp     |    Suspend Timestamp   |       Awake Time       |
  --------------------  |  --------------------  |  --------------------  |
   2016-01-15 09:31:32  |   2016-01-15 09:36:03  |          0h  4m        |
   2016-01-15 09:36:22  |   2016-01-15 19:15:04  |          9h 38m        |
   2016-01-15 19:22:21  |   2016-01-15 20:00:05  |          0h 37m        |
   -------------------  |  --------------------  |  --------------------  | 

Summary: Days Since Boot [8.23] | Days Awake [4.14] | Suspend/Wake Cycles: [28]

The script is in github. link to github repo

  • 1
    This worked for me on Ubuntu 16.04 – raphinesse May 10 '16 at 12:46
  • Good to know that we can check the journal. – Shiplu Mokaddim Aug 31 '16 at 12:07
  • Use journalctl -b 0 -o short-iso MESSAGE="PM: Finishing wakeup." | tail -1 | cut -d" " -f1 for just the time of the last wakeup – raphinesse Oct 18 '16 at 17:10

The pm-suspend program is not the only option how to suspend the computer. My log of this program is now empty, but I have found more reliable command:

cat /var/log/syslog | grep 'systemd-sleep' | grep "Suspending\|resumed"

And the output is:

Oct  2 09:11:48 dmatej-lenovo systemd-sleep[931]: Suspending system...
Oct  2 09:53:10 dmatej-lenovo systemd-sleep[931]: System resumed.
Oct  2 15:02:48 dmatej-lenovo systemd-sleep[27516]: Suspending system...
Oct  2 16:07:19 dmatej-lenovo systemd-sleep[27516]: System resumed.
Oct  2 16:32:48 dmatej-lenovo systemd-sleep[29622]: Suspending system...
Oct  2 17:16:41 dmatej-lenovo systemd-sleep[29622]: System resumed.
Oct  3 00:24:58 dmatej-lenovo systemd-sleep[21316]: Suspending system...
Oct  3 08:17:22 dmatej-lenovo systemd-sleep[21316]: System resumed.
Oct  3 09:09:25 dmatej-lenovo systemd-sleep[24739]: Suspending system...
Oct  3 09:50:47 dmatej-lenovo systemd-sleep[24739]: System resumed.

modified better verision of steps answer

grep ': Awake' /var/log/pm-suspend.log

edit haha thanks for the comments :D

  • And you won a useless use of cat point! – gniourf_gniourf Jun 26 '14 at 15:59
  • No upvotes for useless use of 'cat'. – Magellan Jun 26 '14 at 16:01

I did not have pm-suspend.log on my machine.

This worked for me:

/usr/bin/pmset -g log | grep Wake | grep "due to" | tail -n1

Also says what woke the computer up. :-)

  • 1
    What if there's no command pmset found and no such file as pmset and pm-suspend.log is empty? :( – cprn Oct 27 '15 at 12:51
  • pm-suspend.log was missing and this works for me (on my iMac) – dayuloli May 7 '16 at 13:05
  • This is for Mac only – plaisthos Dec 31 '17 at 14:46

What are you using to initiate the standby?

If you can use a script, then after the line

echo -n "standby" > /proc/acpi/sleep

you could have the line

echo `date +%s` >> /var/log/wakeups.log

Or something similar. This would mean that the first thing the machine did when it woke up was to write the current time and date to a log file (n seconds since epoch).

Then tail -1 /var/log/wakeups.log would give you the last time. You could could subtract this from the current time to get seconds since the last wakeup.


Search for the last occurence of the string "PM: restore of devices complete" in /var/log/messages. If your machine has been up too long, then the log may be rotated, though.


You can use tuptime for track the system startup/shutdown life.

  • Does not provide the information the OP requested. – wieczorek1990 Jun 24 '16 at 8:39

Extending Steps answer:

grep Awake /var/log/pm-suspend.log | tail -1

This will get the line with the last wakeup time.


I think this is a very solid way to do it:

systemd[1]: Started Run anacron jobs at resume

Search for when the OS starts anacron, will happen however the machine is turned on


on fedora using ripgrep

rg Suspend /var/log/messages


34338:Jul 26 03:03:46 <hostname> systemd-sleep: Suspending system...

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.