在具体的某一天用介词on,在某一天的中午、早上、晚上等也用on,单只在上午、下午等用in
On具体在某一天,如：on a rainy day
On April Fool's day
On April 1st,2013
at后加时间点,具体在某一个时刻,如at 12o'clock at midnight at noon
in 后加一段时间,年,月,四季等.如：in the evening in the morning in the afternoon
in July in spring
匿名回答于2021-09-28 01:58:14
