It’s one hour before receiving Holy Communion
Canon Law 919:
Can. 919 §1. A person who is to receive the Most Holy Eucharist is to abstain for at least one hour before holy communion from any food and drink, except for only water and medicine.
So technically speaking if mass were to start at 11:00, but you would receive communion in your parish 45 minutes after mass starts, at 11:45. Then your one hour fast would begin at 10:45, one hour before you were to receive communion. And yes, the one hour fast applies to daily mass also.