That was the proposal by OGGO in a 2012 report, that the budget date should be fixed. There is really no reason for not having it fixed, but obviously the government wants to have the flexibility of choosing the date of the budget. You know, this is their choice, but the problem is that when you fix the main estimates date but not the budget date, then you don't really have much room to play with, because you don't know when the budget is going to be tabled. Again, moving the date four or five weeks forward is not going to change the system significantly.
On June 20th, 2017. See this statement in context.