The reason the Bank set a time span was to show its determination to achieve the target and increase the confidence of the markets and the public.
To fulfill this objective, the main operating target for money market operations was switched from the uncollateralized overnight call rate to the monetary base; it was then decided that the size of the monetary base would rise at an annual pace of about 60–70 trillion yen, to be doubled in two calendar years (2013–14).