On budget day, but before the presentation of the budget, the Treasurer spends the day behind locked doors briefing media and interest groups on various aspects of the budget. This is known as the budget lock-up. Because of the market sensitive nature of some of the information which they are being provided, those invited to attend the briefings are not allowed access to the outside world until the budget has been presented in Parliament by the Treasurer, which normally commences at 7.30 pm.