I am courteously asking you for a seven-day extension for the delivery.
'Proroga' = PRO-ro-ga; stress on the first syllable.
Use when you need more time to deliver something and must formally request an extension from a client, partner, or institution.
'Proroga' is the Italian term for a formal extension of a deadline. 'Cortesemente' (courteously) makes the request polite. This word is particularly common in public administration and construction, but applies broadly.
Sarebbe possibile posticipare la scadenza al [data]?
Would it be possible to postpone the deadline to [date]?
Question form; less formal, more conversational
Avrei bisogno di qualche giorno in più.
I would need a few more days.
Very informal; suitable only for trusted colleagues
Chiedo un'estensione dei termini di consegna.
I am requesting an extension of the delivery terms.
'Estensione' is used in modern corporate Italian
Italians tend to be understanding about deadline extensions when given a genuine reason. However, in public sector contracts, proroghe must often be formally approved and documented — a verbal 'sure, no problem' is not enough.