national event; event enjoyed nationwide
Refers to an event that is widely recognized and participated in across Japan, often with a sense of shared cultural significance.
The Kohaku Uta Gassen can be called a national event.
New Year's is a nationwide event in Japan.
国家的行事 emphasizes official or state-sponsored events, while 国民的行事 focuses on broad popular participation and cultural recognition.
Compound of 国民 (kokumin, 'nation's people') + 的 (-teki, '-like, -al') + 行事 (gyōji, 'event'). The exact historical derivation is uncertain, but the term follows a common pattern for describing something as characteristic of the nation.