Time behaving strangely in terms of sunrise/set

Salutations! I've just installed Stellarium, and so maybe I've got something strange going on with my configuration - I've changed my default location by plugging in lat and long, but when I start tweaking the time, the sun is rising when it shouldn't - starting around midnight. And the moon isn't showing up at all, which is probably just a checkbox I need to click on somewhere.

I'm know it has something to do with the fact that the program starts up with my system time, so when the time shows 1300 hours, it's showing it as night at the set location - which is correct, as my system's time/location is in the US, but the location I'm looking at in the program is a location in the UK, so I need to know how to correct the time to UK time, so that it pulls correctly, and not seven hours behind.

Hopefully that makes sense! Basically, I need to know how to tell Stellarium not to use MY time, but to use the time that's current for the location I have set in Stellarium.