Shutdown
Location: Launchd-shutdown.system.log
This log file contains information about the shutdown process. You can find the date and time down to the second at which the system finished the shutdown process. You can also see an approximation of the duration of the shutdown process.
To access this log and reveal information about recent shutdowns, copy and paste the following into the terminal.
open /private/var/log/com.apple.launchd/launchd-shutdown.system.log
Use the Command + F function to search “shutdown finished”. To find the time of the last successful shutdown.