National Day
A Daily Challenges event that only opens on days when a country celebrates its national day: three short questions about that country.
When it appears
Only on real national days, of which there are about 140 a year. On those days its card comes first in the Daily Challenges; the rest of the time it tells you how many days are left until the next one. The challenge is the same for everyone and the date follows UTC, like the other daily challenges. When two or three countries celebrate on the same day, each question can be about a different one.
The three questions
First, which country it is: you pick its flag from four from the same part of the world, and a sign tells you which continent it is on. Then, what it celebrates: its independence, becoming a republic, a revolution, its unification, its constitution or another milestone, sometimes with the year. Finally, an extra fact: how many years the event is turning, its capital, its currency or one of its official languages. Every question has four options, and the wrong flags, capitals and currencies come from nearby countries, so ruling out by continent isn't enough.
Scoring
You win with 2 out of 3 or better. This challenge's streak counts events in a row, not days, so it doesn't break during weeks with no national days. Like the other daily challenges, winning it also extends your overall daily streak.
Tips
Many countries in the Americas and Africa celebrate their independence, and the year is the best clue: in Latin America most date from the early 19th century, and in Africa many are from around 1960. In Europe other reasons are common, such as a unification, a constitution or a date tied to the monarchy. If you're unsure about the flag, the continent on the sign already rules out half the options.
What you learn
Short, concrete history: when and how each country came to be, and which currency and language it uses today. After a few of these, random dates on the calendar start to come with a country and a reason.