also: きちにち · きつじつ
noun
Refers to a day considered favorable according to the traditional Japanese calendar (e.g., 大安, 先勝). Often used when scheduling weddings, ceremonies, or important events.
結婚式は吉日を選んで決めました。
We chose an auspicious day for the wedding.
今日は大安で吉日だ
Today is a lucky day (taian), so it's a good day for moving.
noun
unspecified day of the month
Used in formal correspondence (letters, invitations) to obscure the exact date of writing, implying the document was prepared in advance. Typically appears as 吉日 in the date line.
案内状の日付には「平成三十一年七月吉日」と書かれていた。
The date on the invitation read 'a lucky day in July, Heisei 31'.
公式の書類に吉日と記載するのは、発送日を特定させないための慣例です。
Writing 'kichijitsu' on official documents is a convention to avoid specifying the exact date of dispatch.
Rare reading; may appear in older or formal contexts.
Composed of 吉 (good fortune, auspicious) and 日 (day). The reading きちじつ is the most common on'yomi combination; きちにち mixes on and kun readings, and きつじつ is a less common on'yomi variant.