I was wondering if there is some log file where I can find the dates and times of hibernation on and off. I mean, I usually hibernate my machine instead of shutting it down, and I need to know if there is a registry or log file that can tell me when I used my computer in the last few days.I use Debian Jessie (8.7). 
Hibernation date and time registry in Debian 8
debian;users;login;hibernate
This information is included in /var/log/syslog (and its rotated versions). I get my recent suspend to RAM periods byzegrep -h 'Suspending system...|System resumed' /var/log/syslog*You should probably use Hibernating system... instead, check your logs to make sure.