It was billed by Brexiteers as "Independence Day" - until political paralysis prompted a last-ditch delay to Britain's planned departure from the European Union.
Now people are set to mark March 29 - the original date for Brexit - in all manner of ways, from protests outside parliament to tongue-in-cheek "leaving" parties.
Nearly three years after the divisive referendum that saw 52% of people back leaving the EU, Britain's political institutions are deadlocked on the issue.
MPs are due to vote for a third time on an unpopular divorce deal on Friday - the same day Britain was due to leave the bloc at 11pm (2300 GMT) after 46 years.
Prime Minister Theresa May kicked off a two-year countdown to exit on March 29, 2017, by triggering Article 50, the mechanism in EU law to leave the bloc.
She repeated the date time after time in parliament and in speeches around the country, stressing that Britain would leave on that day, come what may.
But after her divorce deal agreed through months of painstaking negotiations with the EU was twice overwhelmingly rejected by MPs, May was reluctantly forced to delay Brexit beyond the much-heralded date.
That has left this Friday as an opportunity for each side - and those in between - to celebrate, rally in frustration or, perhaps, find a moment for reflection.
'The end of the world'
Dismayed eurosceptics will vent their anger at the delay to their dream by massing outside parliament on Friday afternoon - some after completing a two-week, 270-mile protest march from northeast England.
Small numbers of fiercely pro- and anti-Brexit demonstrators have already been keeping up a constant presence in Westminster in recent months.
Ardent Brexiteers want Britain to leave the bloc now without any divorce deal in place, falling back on World Trade Organisation (WTO) terms.
At the other end of the political spectrum, europhile London Mayor Sadiq Khan will launch a campaign bus on Friday emblazoned with the slogan "We are all Londoners".
It will tour neighbourhoods of the capital heavily populated by Europeans, highlighting government measures to mitigate the impact of Brexit on them.
Once the sun has set and the original 11:00pm departure time for Brexit looms, Britons will have the chance to drown their sorrows or revel in renewed optimism about potentially stopping the process.
Bars and nightclubs in Remain-dominated London have laid on a host of Brexit-themed parties to celebrate the non-event.
A club in Bethnal Green in the capital's east has promised "bonkers Brexit cabaret" with appearances by characters including "Monster May".
"Fill out your visa applications (get a ticket) or you may be rejected at customs - it is time to party like it is the end of the world, because let's be honest - it might be," organisers warned.
"This party will be taking place on the 29th regardless of the Brexit extension!" they added.
'How to disagree well'
Elsewhere, the Church of England has invited parishioners to "cafe-style meetings" over the weekend in a bid to forge some unity over that most British of things: a cup of tea.
Suitable Bible passages and newly-composed prayers will be chosen under the slogan "Together" to prompt the faithful - whatever their views about leaving the EU - to start conversations.
Archbishop of Canterbury Justin Welby, the spiritual leader of the world's Anglicans, said on Twitter on Wednesday that "reconciliation is... about finding out how to disagree well".
He also encouraged more respect for lawmakers.
"Let us pray for them... for a decision that has widespread support and for a process that brings national agreement," Welby added.
Meanwhile the Museum of London has been eagerly capturing this moment of uniquely heightened political division and drama in its permanent collection of oral histories.
Researchers on a traditional red double-decker bus have toured London's street to capture everyday people's "thoughts, views and opinions" on Brexit.