score:6
It seems that you were admitted as a visitor, since you were given six months. It would still be reasonable to describe the purpose of your visit as "transit," however, since that was in fact the purpose of your visit.
Upvote:3
It's a pretty grey area, but if your only purpose for being there was to get on another plane, and you couldn't have reasonably got on an earlier plane, then yes your reason for being there was transit. If they are asking your reason for then 'transit' would be a good answer. If they are asking what visa you had then there ought to be a box for 'didn't need a visa'. Frankly since you don't need a visa for the UK your answer is going to make no significant difference.
Upvote:9
UK specifically limits transit to 48 hours
You might need a Visitor in Transit visa if youβre from outside the European Economic Area (EEA) and Switzerland and youβll:
be changing flights in the UK on your way to another country
go through immigration control, for example to check in your luggage for a connecting flight
leave the UK within 48 hours
not work or study while in the UK
I would use that criteria. In your case I would say it is 3 days and hence not transit however either way no big deal.