Hi Barbara! When Members of the House of Representatives and Senators meet in Parliament House, the sittings last for an average of eleven hours a day. Sometimes daily sittings go for much longer, with members and senators meeting long into the night!
Before the beginning of each year and after an election, a sitting calendar is distributed to let everyone know when Parliament will be sitting. There are on average 18 to 20 sitting weeks a year. Sittings are usually held Monday to Thursday in one or two week blocks.
Each parliament is the length of a House of Representatives term, which is three years or earlier if an election is called.