November 8 is looking the most likely date for the election but Prime Minister Helen Clark is still keeping it to herself.
The election must be held by November 15.
Asked whether she would release the date to her weekly media briefing, Miss Clark said there was nothing to share yesterday on that matter.
The House sits this week under urgency to pass last-minute legislation.
Included are the emissions trading scheme legislation, the Waste Minimisation Bill and the Public Transport Management Bill.
No sitting days are allocated for next week and September 23 is earmarked on the New Zealand Parliament website as the last sitting day.
Even if Miss Clark held off announcing the election date to September 23, it would still allow a six-week campaign for a November 8 election.
On November 1, the All Blacks play a rugby test against Australia in Hong Kong.
The test will be start at 9.30pm New Zealand time, but it is unlikely the Government will want people distracted by both election and test results.
The All Blacks play Scotland, in Scotland, on November 8 but that is Sunday, November 9 in New Zealand.
One of New Zealand's richest horse racing meetings will be held at Riccarton on November 15, as part of Canterbury's show weekend; another unlikely date for an election.
National Party leader John Key has consistently picked October 18 as the election date, but that looks more unlikely as Labour starts to close in on National in the polls.
Last week, the New Zealand Roy Morgan Poll showed National Party support at 44.5% (down 3.5%) in early September, only 6.5% ahead of the Labour Party 38% (up 4%).
This is the closest the two major parties have been since October 2007.
If an election were held now New Zealand would have a coalition government likely to be led by the National Party.
Approval for the NZ First Party of Winston Peters has dropped significantly in the wake of the party funding scandal with support down 4% to 2.5%, the lowest since September 2007.
Support for the Greens was 8% (up 0.5%), Maori Party 3.5% (up 1.5%), Act NZ 1.5% (un-changed), United Future 1% (up 1%) and others 1% (up 0.5%).
Polling, including Labour's own polling, had not shown that the party had been hurt by its association with NZ First.
Mr Peters has stood down as Foreign Affairs Minister while various investigations into donations to the party are under way.
Miss Clark would not comment on whether she would consider going into coalition with NZ First after the election, something National Party leader John Key has said last week he would not do.
If Miss Clark is not ruling out NZ First from a future coalition agreement, she will watch carefully for poll trends before announcing the election date.
