In Sweden, National Day is celebrated on the 6th of June.
On this date, some important things have happened.
Firstly, Gustav Vasa, arguably the father of the modern Swedish nation, was elected (i.e. confirmed) king in 1523. This meant the end of the quite lopsided Kalmar Union, in which the Nordic countries had united in 1397, and the birth of an independent Swedish nation.
In 1809, an important new instrument of government was adopted on this very date. The act abolished the monarchical despotism of Gustav III (which had him shot dead in 1792), and replaced it with a more sensible constitution based on separation of powers. The instrument remained in place until the 1970s.
In 1974, the aforementioned instrument of government was again replaced with a new one, adopted on the 6th of June. This modernised the constitution by, among other things, abolishing many of the powers of the monarch, but keeping the monarch as the head of state. In the older constitution, the monarch still held considerable power, but exercised relatively little of it. (Comparable to the modern British monarchy, for example.)
Back when I first started this course (back about 2-3 years ago), this final lesson seemed a world away. Almost didn't think I'd ever get to this point, but here I am. I've gotten to the point where I can hold a fairly balanced conversation with a native Swede, and it's all thanks to this wonderful course and its amazing moderators. Thank you guys very much. Vi hörs!
That would be swapping a noun (Sweden) for an adjective (Swedish) and Duo generally doesn't like that. I find for most possessives (where something belongs to something else) either "the X of Y" or "Y's X" structures are accepted, i.e. "Sweden's national day" or "the national day of Sweden". There's no doubt the meaning of your answer is the same in this case, it's just the structure is bit too different.
I'm not 100% sure how those in the US feel about it, but I think it's the same thing as Independence Day. It's a single, specific day.
"En helgdag" is somewhere else in this section, and I think that's what you mean by a national holiday, i.e. any official day where most people have a day off work.
In many countries a "public holiday" is known as a "bank holiday".
In Canada, a national holiday is any day off prescribed by federal legislation. We also have provincial holidays that vary from province to province. Both kinds are public holidays.
I think "national day" is the best translation, since a national day and a national holiday are different things.
In the US banking industry we use the term "Bank Holiday" to mean a day that banks are closed especially in contrast to "Market Holidays" which are days that the New York Stock Exchange is closed. Most of them are the same, but there are a couple bank holidays that aren't market holidays and vice versa.
If you said "National Holiday", would that mean just one day to you, and not various special days throughout the year? Would it make sense to say "Independence Day is the National Holiday"?
Also, if you say "holiday", that suggests a day off work to me. Does "holiday" mean a day off work you, or can it also mean a symbolic day? Wikipedia informs me that Sweden's National Day has been around since 1983 ("Svenska flaggans dag" before then) but has only been a public holiday since 2005.
Not necessarily. An Independence Day is a day that commemorates and/or celebrates political independence. A National Day on the other hand just celebrates the nation, and isn't necessarily tied to commemorating a certain date of independence. Sometimes, these coincide, such as 4th of July in the USA, but sometimes they don't, e.g. 14th of July in France commemorating the storming of the Bastille but not the birth of the nation.
national– is only used in compound words. The adjective nationell is never used in compound nouns. We usually have some kind of base form that is used for creating the composites, rather than using the same adjective we'd use with the noun in question. Compare how 'red wine' is either rött vin or rödvin.