noun
auspicious occasion; happy event
A somewhat formal or literary term for a celebratory occasion, such as a national holiday, wedding, or New Year. Not used in everyday casual speech.
新年の佳節を迎え、謹んでお慶び申し上げます。
On this auspicious occasion of the New Year, I respectfully extend my congratulations.
この佳節に当たり、皆様のご健康とご多幸をお祈りいたします。
On this happy occasion, I wish you all good health and happiness.
祝日 is the common word for 'national holiday' or 'public holiday', while 佳節 is a more formal, literary term for any auspicious occasion.
慶事 refers to a happy event or celebration in a more general sense, often used in formal contexts, but 佳節 carries a stronger nuance of a special, auspicious time or season.
The exact derivation is uncertain; the kanji 佳 (beautiful, good) and 節 (occasion, season) combine to mean 'auspicious occasion'. The variant 嘉節 uses 嘉 (praise, auspicious) with a similar meaning.