The central bank confirmed a mid-year tightening of its OCR but left the mid-year period undefined. There was a 50-50 call on whether the first 0.25% lift would be in June or July.
BNZ market economist Stephen Toplis said it was clear the Reserve Bank was not sure whether June or July would be the best time to move its interest rates.
"Today's OCR review was about as ambivalent as possible about the specifics while being absolutely consistent with past commentary that the tightening cycle will start at the middle of the year.
"On balance, it looks as if the Reserve Bank has become a tad more optimistic about the outlook but mindful that such optimism is tainted by a higher risk profile, especially surrounding recent developments in European financial markets."
It would be difficult for the Reserve Bank to know how the economy was evolving between now and June because little data was due for release, he said.
The only possible deal-breaker was the first-quarter labour-force survey due next Thursday. The December quarter's unemployment rate was 7.3%. If the rate remained the same, there would be a strong argument for delaying any increase until July.
First-quarter retail-sales data, further housing market information and yesterday's credit data were unlikely to provide enough information to force a decision, Mr Toplis said.
However, Craigs Investment Partners broker Chris Timms believes the Reserve Bank admitted in its statement by governor Alan Bollard that it was becoming less relevant to the way retail banks set their lending and borrowing rates.
Dr Bollard said he expected to begin removing policy stimulus from the economy over the coming months, provided the economy continued to evolve as projected.
Mr Timms believed the Reserve Bank had admitted that the increased wedge between the OCR and lending rates should reduce the extent to which the OCR would need to be increased relative to previous cycles.
Reserve Bank liquidity rules meant that retail banks must retain a sufficient portion of their total assets in the form of liquid assets to be able to meet the potential calls from savers to withdraw their money.
That would mean banks competing for funds and longer-term interest rates - both borrowing and lending - increasing ahead of short-term rates.
The OCR would be used for the job it was intended for, keeping inflation under control through short-term interest rates, Mr Timms said.
ASB chief economist Nick Tuffley said the Reserve Bank had given itself room to manoeuvre with its signal it expected to begin removing stimulus over coming months.
"Effectively, that signal is still around the middle of 2010. The Reserve Bank is more optimistic on the strength of the near-term recovery than we are. From an inflation point of view, the Reserve Bank appears to us to be under-cooking the extent of future pressures."
Mr Tuffley favoured a July increase and a series of 0.25% moves to a OCR of 5%.
But with inflation quickly becoming a very uncomfortable picture, a June increase could not be ruled out.
"Markets will be left guessing for now, with OCR expectations swinging on every key release over the next six weeks," he said.
