When does the rubbish truck come?
NET-tets-tsa ur-BAH-na — double 't' before 'ez'; stress the first syllable of nettezza and the second of urbana.
Ask this of a neighbour, your landlord, or the building caretaker (portiere) when you need to know the collection days. It is essential information when you first move into an Italian apartment.
Nettezza urbana is the traditional Italian term for the municipal waste collection service. You will also hear the modern terms igiene urbana (urban hygiene) or raccolta rifiuti (waste collection). All are correct and widely understood.
Che giorni raccolgono i rifiuti?
Which days do they collect waste?
More direct; raccogliere means to collect/gather.
Quando passa il camion della spazzatura?
When does the rubbish lorry come past?
Very colloquial; spazzatura is informal for rubbish/trash.
Qual è il calendario della raccolta?
What is the collection calendar?
Formal; used when asking for the full printed schedule.
Most Italian comuni now have a dedicated app or website where you can check the exact collection calendar for your address. In many cities — including Milan and Rome — collection days differ by neighbourhood, so a general answer may not apply to your street.