High noon, for the Queen, will actually come at 1am.
While the UK sleeps on Sunday night, tens of millions of Americans will be watching Oprah to see their homegrown kinda-princess, the former actress who rose to the highest echelon of royal life only to spectacularly turn her back on it, talk about how the fairytale went so horribly wrong.
As Harry and Meghan, Duke and Duchess of Sussex appear on screens it will be less than three years since they stood in front of his entire royal family and a global audience of billions to say their wedding vows. Today, they're living down the road from Ellen DeGeneres and Drew Barrymore, getting set to rake in tens (perhaps hundreds) of millions and are embroiled in the messiest public royal skirmish in history.
This week three teaser trailers for the Sussexes' Oprah interview landed, giving us a preview of the tone and tenor of the prime-time tell all. He is seen, po-faced, saying his biggest fear was "history repeating itself". She appears on camera accusing "The Firm" of "perpetuating falsehoods about us".
On one hand this is nothing particularly new. A recitation of already-run charges that they were hard done by. Last year, a friend told Vanity Fair that Meghan was "convinced there was a conspiracy against her,'' while in court documents she said she had felt "unprotected" by the monarchy during her pregnancy.
However what is a marked departure is the virulence and directness of the broadside being lobbed by the California-based Sussexes.
While the substance of Monday's two-hour interview might essentially be a recycled melange of previously aired criticisms, make no mistake, this is a significant escalation of the trans-Atlantic conflict that has been bubbling away since Megxit.
The palace is not exactly blameless in this increasingly squalid media street fight.
This week the Times unveiled explosive allegations that Meghan had bullied palace staffers and that she had worn elaborate diamond earrings allegedly given to her by Saudi Crown Prince Mohammed bin Salman weeks after his regime murdered dissident journalist Jamal Khashoggi.
While the Times' Valentine Low reported that the anonymous sources for the piece had "approached [the paper] … and they wished to tell their side," the timing of the whole thing smacks of palace forces trying to land a body blow on the Sussexes ahead of their Oprah interview.
Meghan, via a spokesperson, has strenuously denied the bullying claims, calling the report "a calculated smear campaign based on misleading and harmful misinformation" and labelling it "a defamatory portrayal of the Duchess of Sussex."
"It's no coincidence that distorted several-year-old accusations aimed at undermining the duchess are being briefed to the British media shortly before she and the duke are due to speak openly and honestly about their experience of recent years," the spokesperson said.
The question that has not been answered is if these are not new allegations, why did the palace not act sooner to prevent things coming to such a damaging head from the palace's perspective?
Likewise, Low also reports knowledge that the earrings in question came from the Saudi Crown Prince dates back to 2018. Clearly the palace waiting until now for someone, cough, to lob this particular grenade at the duke and duchess represents royal forces of some sort entering the grubby fray.
Irrespective of how we got here, this weekend, we are on the brink of all-out trans-Atlantic warfare of a brutal nature the likes of which we have never seen before.
Never in the history of the royal family has so much dirty laundry been aired so fast and with such fervour and the consequences of which might prove stubbornly permanent.
What sets this battle apart is that based on what has come out in recent days, Harry and Meghan aren't just breaking the omerta that surrounds royal life they are naming names.
In denying the Times' bullying claims, lawyers for the couple directly pointed the finger, saying that the newspaper is "being used by Buckingham Palace to peddle a wholly false narrative."
When Diana, Princess of Wales sat down in 1995 to speak to the BBC's Panorama and to dish the dirt on her husband's philandering ways and her horrible treatment by the royal family, she never once took aim, directly, at Her Majesty.
And while she might have famously – and epicly – said "there were three of us in this marriage" nor did she straight out say "My husband has spent the better part of the past 15 years panting after Camilla."
There was a certain, slim level of restraint that looks like it is about to evaporate in a miasma of ratings and heartbreak.
And it's all just so bloody sad because after Monday, how does either side step back from this? The repercussions of the Sussexes' Oprah confab could well be ultimately measured in years and decades rather than weeks and months.
On a personal level, the already fraught nature of Princes Harry and William's relationship has never been far from the headlines over the past few years. It is impossible to see how watching Harry potentially taking aim at the house of Windsor will do anything but worsen the situation and exacerbate tensions.
And what of Harry and the Queen? Late last month Harry appeared on James Corden's Late Late Show for his first post-Megxit TV interview and sweetly revealed that Her Majesty had sent the family a waffle-iron for Christmas. Will they be able to expect, say an airfryer winging its way from Windsor to Montecito all wrapped up in a big bow after Monday?
Another consequence of the events of this week, a situation likely to become more entrenched post-Oprah, is that they have irrevocably cemented the view in America that Meghan is wholly the victim of a racist establishment and to some degree, a racist country which was never going to fully accept a bi-racial duchess.
Any semblance of a middle ground or the notion of being able to publicly hold a more nuanced assessment of the situation or view about the main players has evaporated.
Then, let's talk about their titles. If Harry and Meghan do directly zero in on the royal house during the Oprah conversation, how can they possibly still in good conscience use their titles as the Duke and Duchess of Sussex? If this is an organisation that has done them so wrong, how can they continue to happily tout their membership of it via using their spiffy royal appellations?
The only guarantee about what will follow after Monday is this: Chaos. Chaos and more chaos.
It seems mad to think that any dignified lines will be able to be drawn under this whole chapter, either by Harry and Meghan or the palace, in the wake of the Oprah interview, or that anyone involved will be ready to soberly move on with dignity.
The temperature has already been ratcheted up far, far too high for tempers to suddenly simmer down and for cooler heads to prevail.
On both sides of the Pond, forces are marshalling and the troops are digging in.
World War Me-ghan is here.
• CBS presents Oprah with Meghan and Harry will broadcast Tuesday, March 9 at 7:30pm on Three."
Daniela Elser is a royal expert and writer with more than 15 years experience working with a number of Australia's leading media titles.