at, in, on在表示时间时的区别

表示时间：

at:

1) 表示某个时间点(point of time): at seven o'clock, at 5:30 pm

2) 表示进餐的时间: at breakfast, at lunch, at supper, at dinner

3) 表示一天中的某个时间点，如子夜、破晓、日出、正午、日落等: at noon, at midnight, at daybreak, at dawn, at sunrise, at nightfall, at sunset

in:

1) 表示较长的时间(period of time), 如年、月、日、周、季节、上午、下午等: in 1995, in a year, a two weeks, in the morning

on:

1) 特定的某一天: on Mondy, on April 5, on New Year's Day

2) 某一天的早晨、中午、晚上: on the morning of July 6, on a dull afternoon of April 7, on a cold night, on a quiet evening