Network client is released unexpectedly and mac goes to sleep
Where do I find logs why the sleep happens?


how to find out the start time of last sleep


  You can use the pmset command to obtain this information. The
  following command obtains a log of the sleep/wake entries then
  restricts this to the last entry in the list which should be the most
  recent sleep:
  
  pmset -g log | grep sleep | tail -n 1
  
  You can obviously play around with anything after pmset -g log to give
  you what you need.