What does 同日 mean?
同日 is a Japanese noun meaning “the same day” in English. It is written as 同日 in kanji, どうじつ in hiragana, and doujitsu in romaji. This word is part of JLPT N3 vocabulary.
Example sentence
同日にアポロ１１号が月面着陸に成功した。
On the same day, Apollo 11 succeeded in landing on the moon's surface.