EDIT: It's 72 hours but there are some helpful links below for others who were confused on the difference.
I know this was discussed on the other threads but there wasn't a consensus. My notifications from the airlines said 72 hours and some of the travel articles out there are saying 72 hours. But the "Ministero della Salute" website says 48 hours and my Passenger locator form says 48 hours. So I am assuming this is the new rule at this time. I wanted to bring this to people's attention so everyone was aware but also see if you have all been seeing "48 hours" more as documents/websites are updated. For those of us with long itineraries, 48 hours is more of a crunch when you consider test center hours, if you work the day before you leave, etc.
Has anyone had experience with doing the witnessed at home tests (the ones we are allowed to use for the return flight) for this purpose? In what format do you receive that result?