Blimey, even Delia's fast roast chicken is 45 minutes on gas mark 8 (and that's for a much smaller 3lb chicken).
I'm guessing, since there's a bit of the '6' missing on the bottom left of the number, there's also a '1' completely missing/unprinted in the 'hours'. But bloody dangerous, what if someone who didn't know better had bought that particular bird? Salmonella side orders all round.