And she said the office would also be open during normal business hours on Friday and until midday Saturday to handle any special votes people need to make.
"But it's important to remind voters that if they haven't lodged their voting papers yet they will have to hand-deliver them to our office no later than midday on Saturday."
In the 2013 local body elections Whanganui voters were among the more diligent in the country with 58 per cent of the papers returned.
Ms Moosman said she expects preliminary results will be available on the Whanganui District Council's web page between 3-4pm on Saturday. The results for the Whanganui District Health Board will follow later in the afternoon.
Voting for mayor and council uses the "first-past-the-post" system while the voting for the health board is decided on the single transferable voting format.