Norton keep computer signed in for updates?

This info is very important to me to figure out if someone signed in on my computer:

 does Norton 360 keep the computer signed in until it is restarted for updates? I found my computer still signed in after 2 days and the Norton Security notice on desk top recommending to restart for updates. I had signed in two days prior and computer was still signed in...was that Norton 360 or someone else signed it in? (The sign in requirement was set for 1 day) Thank you for any info!!