Depends what you mean by celebrated, and whether you are willing to accept “battle” or “campaign” rather than “war” as the object of celebration.
The major commemoration of the military in Australia and New Zealand is not Armistice Day (Remembrance Day) or Memorial Day (we don’t have that), but Anzac Day. The date is April 25, which was the date that Australian and New Zealand forces landed at Gallipoli during WWI.
Anzac Day has morphed, over the last century, into not just a commemoration of the Gallipoli campaign, but a more general memorial day for Australian and New Zealand service members. The Gallipoli campaign, however, still holds a central place in the commemorations, and in Australia and New Zealand’s collective consciousness, despite the fact that it was essentially a failed military campaign that resulted in considerable loss of life for the invading forces over the eight month siege.