記念日|きねんびkinenbi

1. nounmemorial day; commemoration day; anniversary
   今日きょうは私達わたしたちの記念日きねんびなので、夕御飯ゆうごはんもスペシャルでいこう。↗

   Today is our anniversary so let's make this a special dinner.

• SynonymアニバーサリーNeutralLoanword for an anniversary or memorial day, mostly seen in shop promotions and corporate or event anniversaries; in everyday speech people just say 「記念日」.
• Related祝日しゅくじつNeutralA national holiday designated by law, usually a day off, as in 「国民の祝日」; a 「記念日」 need not be a day off and can be a personal one.
• Related祭日さいじつNeutralOriginally the day of a religious rite; colloquially often used for national holidays with a day off. 「記念日」 marks something to commemorate and need not be a day off.
• Related祝祭日しゅくさいじつFormalFormal collective term for 「祝日」 and 「祭日」, i.e. legal holidays; common in notices like 「日・祝祭日休業」, with the emphasis on days off.

Use 「記念日」 for a day commemorating something, e.g. 「結婚記念日」; 「祝日」 is a legal national holiday with time off, and notices often write 「祝祭日」. 「アニバーサリー」 turns up mostly in advertising.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

1. 出来事できごとなどを記念きねんすべき日ひ、アニバーサリー。