The act currently stipulates that, if a deficit is forecast in a budget owing to a recession, certain measures will take effect in the fiscal year subsequent to the year during which the recession comes to an end. A recession occurred in 2015-2016, and it ended in the same year. The act, as currently worded, stipulates that the measures will take effect in 2016-2017.
On May 18th, 2016. See this statement in context.