Dogs can digest there food in 6-8 hours,,,I think there the quikests of all mammals ,,,socks will know better than me,,,just keep doing what your doing,,if it's all ok..
I feed mine at tea time ,,,and go lamping from midnight onwards genraly,,,if I was going lamping at 6 pm in the middle of winter,,, I would give the dog a bit of food around lunch time...
In the old days I did like most lads,,,and fed last thing at night,,,so if I were lamping they didn't get fed till I got back,,,,mostly they were ok,,,but I have seen a good few dogs my own including,,getting hypo..but you live and le