The main weekend of the festival is now scheduled for February 25-27.
Nine authors had accepted an invitation to speak this year, including historical fiction writer Deborah Challinor, comedian Tom Sainsbury, pathologist Cynric Temple-Camp and financial adviser Mary Holm.
Ewing said despite the date change, the majority of authors were still on board.
"That was a big relief. It would have been a lot of work to organise nine other authors.
"Most events can just be transferred four months ahead, and that's been quite remarkable. It's really good for those who have already bought their season tickets.
"We're just waiting hearing to hear back from our keynote speaker Dr Hinemoa Elder."
One upside of the postponement was that the festival would now be held during the summer months, Ewing said.
"I think the authors really like coming here. It's pretty relaxed, and they enjoy talking to the other authors as well.
"It can be a bit of a solitary occupation, and here they can talk to people who enjoy their books face to face.
"Luckily, they're happy to slot into that third week of February."
For more information on the Whanganui Literary Festival, go to www.writersfest.co.nz