Why does the forum show users as online when they have not been on the website in nearly 24 hours? Not a big deal but minor annoyance when communicating with members.
I think its set at the default, 48hrs or so.
The thing is, the lower the threshold, the more the site performance gets impacted.
If you want to know if a member has been active recently, click on their name, it will give you a date & time of their last activity - its much more reliable than the who's online list.