Just read the signs to see when you can and cannot use a bus lane and a driving instructor can't help you with that - in fact there is one on here (well they said they were) who didn't know how to tell a dual carriageway from a single track road!
Where I used to love there were restrictions only during peak times, so during the daytime you could use the bus lane (and of course at night)
Where I live now, we have just one bus lane along a nasty stretch of road that has massive hold ups in rush hour and it is a bus lane 24 hours with cameras