How do you write Scott Sumner Day in Japanese? Haruhiko Kuroda Day?
The BOJ said it changed the target for money-market operations from the overnight call rate to the monetary base — cash in circulation and the money that financial institutions have on deposit at the central bank. It predicts the measure will grow to 270 trillion yen by the end of 2014. [Toru Fujioka. Masahiro Hidaka. BOJ Doubles Bond Purchases in First Kuroda Easing Salvo. Bloomberg. April 4 2013]
The last Scott Sumner Day fell in September 2012, the day the Federal Reserve announced QE-infinity.
It is not exactly nominal GDP level targeting, but the shift from rate to level is a big one.
I still do not quite fully understand it but I am sure the commentary over the internet will help.