In Alberta, typically we'll have supplementary estimates in a fall sitting. We may have supplementary estimates near the end of the fiscal year, which would be tabled at the same time as the budget address. Interim supply is only required, obviously, if our appropriation bill is not going to receive royal assent before the end of the fiscal year. For example, this year there was no need for interim supply.
On May 7th, 2012. See this statement in context.