So I make it that I am working 181 shifts, plus 3 clawback days, plus 50 'sleep' days where i have spent 6hrs at work at NATS behest.
That makes 234 calendar attendances by my reckoning.
But you only actually attend 181/annum based on full leave entitlement. If you go down your logic you could argue that you lose 2 days leave for a night duty-not good I would suggest. Or alternatively go back to the shambles which was calculating leave in hours.