一個意思,但如果說：在同一天,要用on英漢詞典上給出的例句：On the same day there was another straw in the ill wind. 同一天，這陣惡風(fēng)又帶來一種不吉之兆。 They were both born on the same day and in the same town. 他們倆同一天在同一個城市里出生。