When I'm viewing here in England but not logged in, PPRuNe time is currently GMT+1. Would that be the same for everyone worldwide, or is it something to do with a setting on my PC? [My PC clock stays on GMT all year.
When you are not logged in, you get a default timezone that is set in the configuration of the forum software. Everyone worldwide who isn't logged in will get that same timezone.
When you log in, you will get the timezone you have set in your profile.