the three grand national holidays (pre-1927)
Historical term referring to the three major national holidays in Japan before 1927: 四方拝 (Prayer to the Four Quarters), 紀元節 (Empire Day), and 天長節 (the Emperor's Birthday).
In prewar Japan, the three grand national holidays were widely celebrated as national holidays.
Compound of 三 (three), 大 (grand), and 節 (festival/holiday). The term was used officially before 1927 to designate the three most important national holidays.