The day that can change a Championship. The day that can transform lives.
Just ask Shane Lowry what moving day means to him.
“Honestly, that’s the most incredible day I’ve ever had on the golf course,” surmised Lowry on this day five years ago.
“I honestly can’t explain what it was like.”
The Irishman headed into the third round tied-first at Royal Portrush and what followed will be forever remembered by those in attendance.
In search of his first major, Lowry tore away from the field with an eight-under-par 63 soundtracked by craft songs, cheers and chants as he established a four-shot overnight lead he never came close to relinquishing.
“Every time I had a putt, I just wanted to hole it because I wanted to hear that roar,” said the 2019 Champion Golfer of the Year.
“It was just incredible. It was an incredible day.
“If I’m sitting here this time tomorrow evening, it will be one of the biggest things that’s ever happened to me. "There’s no denying that.”
The rest, as they say, is history, but Lowry is solely focused on the here and now in his pursuit of more glory. Once again, he finds himself atop the leaderboard heading into the all-important third round.
Unlike in 2019, Lowry boasts a two-stroke lead but he might need more than that if Justin Rose is to replicate anything like his scintillating Saturday display from The 147th Open.
En route to his best Open finish, Rose recorded his best-ever Championship score and became the principal early mover at Carnoustie with a seven-under-par 64, just one stroke shy of the record score at the venue in Opens.
Sitting alongside Rose on five-under-par after 36 holes at Royal Troon is Daniel Brown, a fellow Final Qualifier, playing in his first major but with a calmness which belies his lack of major experience.
But beware the chasers. The men with nothing to lose. Aided by favourable conditions, the early starters have packed their boxes and made their move.
Sungjae Im produced the best front nine of the week, going out in 31, while Adam Scott was just a shot worse off as the Presidents Cup teammates stormed up the leaderboard to shake things up in Ayrshire.
In some ways, it is very much a day of two halves. The fearless make their move before the pace-setters face their toughest challenge yet – the mental test.
A glance at the Opens of Royal Troon past shows how the pressure can go one of two ways.
Skip Kendall led by a stroke going into the weekend 20 years ago but shot a 75 to drop back to tied-ninth, inviting Todd Hamilton to start his march to a first major.
Then in 2016, moving day marked the start of one of the great Open tussles as Henrik Stenson and Phil Mickelson powered away from the rest in a prelude to their iconic Sunday showdown which the Swede famously edged in sensational fashion.
The field for The 152nd Open has been whittled down to 80 and the stage is set for more high drama.
Will caution win the day, or all-out attack?
If this year’s moving day is anything like the shows of Royal Troon past, then you can be sure we will be talking about it for years to come.