A friend of mine and I are managers in a restaurant. We are expected to work 55 hours a week and if we miss a day we have to make that day up or have it docked from our pay. However if a manager has to fill in for another manager that misses a day and the absent manager does not make up the day by taking one of your days you do not get paid for the extra day because you are salary. Is this actuall legal?

They may not deduct pay for hours missed if you are on salary but you could be required to work 60 or 70 or more if needed.