I just want to give you a small insight on why this practice actually prevails in Westminster parliaments.
In medieval England, parliaments tried to force the king to spend his own money before taxing. It was a good idea a few centuries ago to vote the budget as late as possible. There's no good reason now to do that anymore. We don't have kings who play a role in public financial management anymore. The OECD and the IMF and everybody agrees that the budget should be approved on time.
This is really an overhang from an old and ancient past that no longer has any relevance in the modern public financial management setting. I just wanted to add that because sometimes we forget where these procedures come from, and of course it made sense 300 or 400 years ago to keep the king waiting, but we no longer have kings; we have democratically elected governments and democratically elected parliaments.