While i used to be logged-in all the time at Tom's Hardware forums, about 5 days ago or so, when i started my PC, i found out that i was automatically logged-out from the forums. Logging back in isn't an issue for me but what is, is the constant logging-in every morning when i boot up my PC since i'm not used to it on this site.
Did some testing to see at which time i'm logged off. Booted up my PC and logged into the forums. As long as my PC is powered on, i'm logged-in to the forums, regardless of if i have my Firefox web browser open or not (v 56.0.2). Figured that when i shut down my PC then i get logged-off from the forums but i'm still unsure about it. Mostly because i had a power outage here 2 days ago that lasted about 3 hours (thinking to get UPS now). Once the power did came back and i returned to the forums, to my amazement, i was still logged in.
At this point, i don't know what that time is when site decides me to log off but it seems it's between 3 to 8 hours when my PC is powered off. That automatic log-off continues on to this date, lasting about a week now.