How can one get last wakeup from screen saver time on Mac OS One can use pmset -g log to get to the info about Wake and Start events of Mac OS. But pmset doesn't seem to make any special assertions to the log when system goes into screen saver mode, and what particularly of interest to me, when the screen saver quits. 

What command or log file I can use to find out when the last wake from screen saver event occurred?
Your two filters to type in the Console log would be:

For screen saver activate: screenshot

For screen saver end: DidWake

Open the Console in the Utility folder and while having selected "all messages" type the above in the filter/search window.