also: きちにち · きつじつ
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.
We chose an auspicious day for the wedding.
Today is a lucky day (taian), so it's a good day for moving.
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.
The date on the invitation read 'a lucky day in July, Heisei 31'.
吉日 is the full word for 'auspicious day,' while 吉 is its abbreviated form used alone in formal letter dating.
very auspicious day for all occasions
Standard kanji spelling; most commonly read as きちじつ.
Alternate reading; less common than きちじつ but still encountered.
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.
Writing 'kichijitsu' on official documents is a convention to avoid specifying the exact date of dispatch.