Analysts refer to the Hwasong-17, also known as the "monster missile," as having conducted what is thought to be its first full flight test on November 18, 2022, in Pyongyang.
The anniversary was declared a holiday at a meeting of the Presidium of the Supreme People's Assembly, according to a report released on Sunday by the North's Korean Central News Agency.
According to KCNA, "the creation of Missile Industry Day marks a unique occasion in our holy journey of national defense development."
North Korea has "demonstrated to the world the majesty of a world-class nuclear power and the nation with the strongest intercontinental ballistic missile" with the launch, it continued.
North Korea frequently conducts significant nuclear tests around significant holidays, and Seoul's spy agency said last week that the nation was completing preparations for a third military reconnaissance satellite launch.
Pyongyang declared it would attempt a third launch in October following a botched second attempt in August, but it was never carried out.
Experts have noted that there is a substantial technological overlap between the development of intercontinental ballistic missiles—which Pyongyang is prohibited from pursuing under numerous UN sanctions—and space launch capabilities.
This year, North Korea has tested more missiles than ever before, defying sanctions from the US, South Korea, and other allies.
Pyongyang proclaimed its status as a nuclear state in its constitution in September, and its leader, Kim Jong Un, called for the development of more advanced nuclear weapons to counter perceived US threats.