noun
auspicious day; good day; lucky day
A formal or literary term for a day that is considered favorable, lucky, or beautiful, often used in contexts like wedding dates or ceremonial occasions.
結婚式には佳日を選びました。
We chose an auspicious day for the wedding.
今日はまさに佳日だ。
Today is truly a beautiful day.
From 佳 (auspicious, beautiful) + 日 (day). The exact historical derivation is uncertain; the spelling is conventionally associated with the meaning of a favorable day.