Sydney Airport opening times are:
T1 International terminal
T1 International is open every day from 02:30AM to 11:00PM (02:30 to 23:00).
Customs opens for departures passenger processing at 04:00AM daily (04:00).
For security reasons, the T1 International terminal is closed overnight from 23:00PM to 02:30AM daily.
T2 and T3 Domestic terminal
T2 Domestic and the T3 Domestic terminals open every day from 4:00AM to 11:00PM (04:00 to 23:00).
For security reasons, the T2 and T3 domestic terminals close to the public from 23:00PM to 04:00AM daily.
During the times the airport is closed, there are a range of accommodation options on and off-airport from budget hotels to five-star establishments which may be booked online.
There are airport hotels located nearby Sydney Airport for travellers in transit.