Japan's gross domestic product will expand 2.0 percent in the year to March 2016, while the inflation rate is seen at 0.8 percent, the BoJ said in a semi-annual report. That compares with a previous estimate of 2.1 percent and 1.0 percent respectively.
The BoJ report -- which followed a meeting where policymakers held fire on fresh stimulus -- appeared to push back an already murky timeline for hitting a 2.0 percent inflation target to the first half of fiscal 2016, which runs from April through September next year.
The ambitious goal was originally supposed to have been achieved around two years after the launch of the BoJ's stimulus in April 2013.
But the bank has, over time, loosened that timeline as the data suggested it was unattainable.