Japan's CPI Revision plan schedule

Currently, the Japan Statistics Bureau is preparing a draft plan. It is collecting opinions from the public during the summer (until 21 August). The result of the collected opinions will be announced in October 2015, and the finalised revision plan will be announced in November 2015.

Further details of the revision and the CPI modelling (such as the weighting of each item etc) will be officially announced in July 2016. In August 2016, it will release historical data using the new CPI base (data only available between January 2015 and June 2016). 

"Finally, at the end of August, it will start releasing the monthly figures using the new 2015 base (starting from July nationwide CPI and August Tokyo CPI). The old 2010 base figures will also be released at the same time up to the release of the December 2016 data", says Societe Generale.