The moment will arrive in New Zealand this evening. At 5.45pm, it will be precisely 60 years since a 33-year-old Ed Hillary found himself quite literally on top of the world.
The summit of Mt Everest surprised him, actually, even though it was a goal so long fought for, so keenly sought. He would say later that he suddenly noticed the ground was no longer rising but falling away in front of him and - well, let him tell the story - "a few more whacks of the ice axe in the firm snow, and we stood on top". It was 11.30am local time and the sun had already set in the land of Hillary's birth. But it was just rising on a brilliant career.
The first significant anniversary of the ascent since the death of the man who became Sir Ed is tinged with only a little sadness. But fittingly in a small gallery at Auckland Museum, an exhibition remembers what it calls his "enduring legacy".
There are sights that have become familiar over the past half century: that ice axe, made by Claudius Simond at Chamonix in the French Alps, its handle of European ash burnished honey-gold by time, the forged steel head and spike scrubbed clean by the ice it has cut; a beautiful Buddhist tanka - a devotional artwork - painted by Kappa Kalden of Khumjung (and, aptly, restored by Ed's daughter, Sarah, a noted conservator); the expedition diary; a piece of grey-green rock from the summit, that Ed brought back for his mum.
But there are unfamiliar objects too: alongside the KBE is a crude hand-hammered badge made for and presented to Ed by the taxi drivers of Kathmandu (a fair recognition, one fancies, for the amount of business he must have drummed up for them over the years).
Most strikingly, in the centre of the gallery, is the mountain itself - or the closest that most of us, marooned at sea level, will ever come to it. It's a strikingly evocative 3D model, twice the size of a billiard table, on which the visitor can follow the laborious ascent.
The word "laborious" scarcely does it justice actually. Charts on the wall explain how it took 17 days to ascend the Lhotse Face, an 1125m wall of blue ice leading to the South Col and the start of the ridge leading to the summit. The model mountain makes this plain, tracking the climbers by means of a snaking red line that moves up and down the contours.
Thus it depicts the stuttering progress of teams that would ascend for no other reason than to lay down platforms across crevasses, or install ropes, or dump supplies for those who would follow after and repeat the process. It was not just by luck that Hillary and Tenzing ended up climbing into history - they were the strongest and fittest of the climbers - but they reached the top with the last steps in a long chain of teamwork.
The model is the work of freelance designer Andy Hoey, a 28-year-old visual effects whizz, who describes his specialist interest as modelling and texturing. This is no illusion he's created - the mountain is an actual object that you can touch, although you may be assured that the museum staff will come down on you like a tonne of bricks if you do. But it comes to life with the texturing - plays of light that bring plain slopes to virtual life, creating digital rocks and snow and even bathing the mountainsides with moving light as the sun rises.
"It arises from techniques they use in film all the time," Hoey says. "You can create something in three dimensions from scratch and you can print it out using 3D printers."
I tell him I'm not entirely sure that I can comprehend what a 3D printer is, and he does his best to hide an indulgent smile.
"There are about six million points on this 3D model," he explains, "and every point is read by the computer and then a machine has a little drill that cuts it out."
Hoey says he "confidently agreed" to a proposal to make the 3D mountain even though the prospect "freaked me out". But his youth didn't mean the ascent of Everest was ancient history.
"We learnt all about it in school and knew who Ed Hillary was and what he'd done. And for that reason, I was very, very excited about doing the project."