For Britain’s Leavers, it is a day of triumph. For Remainers, a day of tragedy.
But after two elections, three prime ministers and three years of attritional political fighting that has split the UK down the middle, it is unlikely that few will mourn Brexit Day’s passing.
That said, January 31, 2020, is very much the beginning - and not the end - of Brexit. Between now and 31 December 2020, the UK and EU need to negotiate the bare bones of a monumental trade deal that will define their future relationship.
As new European Commission President Ursula Von Der Leyen told MEPs on 28 January - when Britain’s Withdrawal Agreement was approved in Brussels - the EU will look to negotiate a deal that benefits its member states, its companies and its citizens.
Both Von Der Leyen and the EU’s chief negotiator, Michel Barnier, have ruled out a full deal being completed in that time. It is more likely that the EU and the UK will come to what Barnier has called a “vital minimum”, with no quotas and zero tarrifs on British exports.
Key sticking points remain freedom of movement — which the EU wants and the UK rejects — and European access to British fishing waters. This week, the government pledged to ‘take back control’ of British fishing, but critics say they are likely to have to buckle.
And then there is the issue of Ireland. British Prime Minister Boris Johnson has publicly committed to ensuring frictionless trade between Northern Ireland — which will exit the EU alongside the UK but remain physically part of the island of Ireland — and the UK.
Johnson will mark the day with a cabinet meeting in Sunderland, the north-eastern English city which was the first to declare support for leaving the EU in the 2016 referendum.
In an address to the nation scheduled for 23:00 CET — an hour before the country officially leaves the bloc — he is also expected to hail the exit as a historic opportunity as well as "a moment of real national renewal and change".
"This is the moment when the dawn breaks and the curtain goes up on a new act," he will say, adding that the government will aim to unleash the country's full potential and "level up" the different regions.
Meanwhile, tens of thousands of Britons living abroad and EU nationals living in Britain remain uncertain about their future.
For some British expatriates, Brexit means not just uncertainty but losing the vote in both the UK and their home countries.
Then, of course, there is Europe itself. In his valedictory speech to the European Parliament Thursday, Brexit Party leader Nigel Farage said that he hoped Britain’s exit would mark the beginning of the end of the European Union.
Finland’s foreign minister, Pekko Haavisto, told leaders at Davos last week that he thought Brexit could be good for the EU. By demonstrating how difficult it is for a country to leave, it could serve to pull together the bloc.
One thing is for sure: for every Brexiteer gathering in London’s Parliament Square on Friday, there will be a remainer at home commiserating.
Britain remains as divided as ever, despite Johnson’s plea to the public this week to move on from Brexit and begin the healing process.
The referendum was won by the slimmest of margins, 51.89% leave to 48.11% remain. That polarisation has arguably become even more stark in the years since the vote: The latest polling by YouGov put leave vs remain at 47% to 40% - 13% were undecided - while on 1 September, 2016, three months after the vote, that figure was 46% to 42%.
The country's exit from the EU has also renewed calls from Scottish independence with Nicola Sturgeon, the country's First Minister, expected to lay out in a speech on Friday "the next steps on Scotland's journey to independence".
"There is the prospect of a brighter, better future as an equal, independent European nation," she will add.
As well as negotiating, there remains a lot of healing to be done before Britain can put Brexit behind it.