Well, the financial year starts July 1. The main appropriation bills and the estimates are presented in May, and the estimates hearings take place in May. The additional estimates come in in February, and then you get the additional estimates hearings. Basically, that's it, but sometimes governments introduce additional appropriation bills outside that program. In that case, the Senate has, on occasion, authorized additional estimates hearings, especially estimates hearings on those additional appropriation bills.
I should say that the appropriation bills are only about 10% of government expenditure. Most government expenditure is contained in special appropriations, which are scattered through a large number of statutes on the statute books. When the main appropriation bills come in, these explanatory notes on the departments cover all the departmental expenditure, not just the expenditure in the appropriation bills.