Unlike other countries, which have anniversaries of independence or revolutions to commemorate, Sweden has never been occupied nor overthrown its monarchy.

So it’s forgiveable that most Swedes still see National Day less as an occasion to celebrate their ancestors and more as a chance to have a barbecue on a day off.

But what does National Day actually celebrate?

The day coincides with the anniversary (last year the 500th anniversary, no less) of Gustav Vasa’s election as King of Sweden in 1523, marking the end of the union with Denmark. One of the most famous kings, he’s often seen as the founder of Sweden as a national state.

But the celebrations definitely don’t date all the way back to 1523.

Rather, the Swedes decided they didn’t want to be upstaged by their Norwegian neighbours (who celebrate May 17th in memory of their first constitution from 1814) when a wave of national romanticism swept in across Sweden in the late 19th and early 20th century.

National Day could have been any day – Midsummer’s Day, November 6th and 30th were also on the table.

But then Artur Hazelius, founder of iconic Stockholm outdoor museum Skansen, amid this national romanticism threw a patriotic party in honour of his native country, culminating in festivities on June 5th “to celebrate our historic memories tomorrow, Tuesday June 6th”.

It is quite possible he saw a chance to earn Skansen some extra ticket revenue on a day when not much was happening anyway.

It was decided that the day was to be celebrated every year, but despite getting a name in 1916 to boost its brand (Svenska flaggans dag – The Day of the Swedish Flag) it was slow to take off, mostly because most Swedes don’t really feel a strong connection to June 6th. It is not a day of rebirth following a national trauma, it doesn’t have the same patriotic ring to it as Fourth of July in the US or Syttende Mai in Norway.

In fact, the day only officially became the National Day of Sweden in 1983.

In 2005, it became a public holiday in order to raise its status, hoping a state-sanctioned day off could tempt Swedes into patriotic pride.

A perhaps more likely reason was that Göran Persson, Social Democrat prime minister at the time, realised that by swapping Whit Monday (a former public holiday which always fell on Mondays) for June 6th (which twice every seven years gets swallowed up by the weekend) he could quietly increase the Swedes’ total number of working days and thus improve the country’s productivity and gross domestic product.

It wasn’t so quiet, in fact, and many Swedes still mourn the loss of Whit Monday, when something happened with the Holy Spirit and apostles that most of them can’t quite remember. But they do remember that they used to have the day off, and a fine day off it was too.

• Why does secular Sweden have so many religious public holidays?

That said, interest in National Day has been growing in recent years – it’s hard to say whether that’s due to rising nationalist movements in society or the fact that Swedes will be convinced to celebrate anything in exchange for akvavit, herring and a day of organised fun.

If you’re a foreigner who recently became a Swedish citizen, chances are you’ll have been invited to a citizenship ceremony in your local town hall, who are obliged under law since 2005 to organise these ceremonies. The event in the Stockholm City Hall is usually popular among new Swedes, perhaps partly thanks to the cinnamon rolls.

Other than that, there are no hard and fast rules about how to celebrate. You’ll be seeing more Swedish flags than usual, and you may also be able to buy a National Day pastry in many bakeries, a small almond cake topped with strawberries and a Swedish flag.

Skansen still organises celebrations every year, usually attended by the Royal Family. 

Or you could do what most Swedes do and wait for Midsummer’s Eve, the more widely popular holiday this month.

In 2016, 31 percent told a survey that they had celebrated National Day that year, compared to 84 percent who had celebrated Midsummer.

Nevertheless, grattis på nationaldagen, Sverige!