in，at和on是时间名词前常用的介词，下面就它们在时间名词前如何使用进行详解。
一、当有定语修饰morning，afternoon，evening，day，night时，其前面的介词用on，指具体或不具体的某一日或某些日。例：
1 Would you like to come to my house for dinner on Fridayevening?星期五晚上你愿意到我家来吃饭吗?
2 It's good to do some reading at home on rainy days，下雨天在家读读书是一件不错的事。
3 That child left home on a cold winter night，那个孩子在一个寒冷的冬夜离开了家。
4 Do you want to have a party on your birthday?你想在你的生日那天举办个晚会吗?
5 All the chlidren in the world are very happy on Children's Day，儿童节那天全世界的孩子都非常快乐。
6 We are going to have a get―together on the afternoon of January19th，我们将于1月19日那天下午聚会。
7 Usually we go swimming on Saturday evenings，通常我们在星期六晚上去游泳。
二、morning，afternoon，evening和表示星期的七个词前有this，that，next，last，tomorrow，yesterday等词限定时，则前面一律不用介词。例：
1 The boy was later for class this morning，这个男孩今天早上上学迟到了。
2 Last Wednesday Lucy didn't go to school，because she was ill，上个星期三露西没上学，因为她生病了。
3 I shall give a talk next Tuesday morning，下周二上午我要作报告。
4 Tomorrow afternoon we are going to watch a football match，明天下午我们将看一场足球赛。
5 There was an accident on this street that afternoon，那天下午在这条街上发生了一起车祸。
三、在时间点前常用介词at。例：
at six o'clock；at half past eight；at ten to nine；at a quarter pasteleven；at twelve twenty
四、在年代前用in，季节前用in，月份前用in，年月前用in；在日前用on，月目前用Oil，年月日前用on，节日前用on。例：
in 2008；in spring/summer/autumn/winter；in September；in Septem-ber，2008；on September 10th；on September 10th，2003；on ChristmasDay；on Women's Day；on National Day(在国庆节那天)
五、其他情况。例：
1 My family moved to France in that summer，那个夏天我们家搬到了法国。(in that summer表特指)
2 How many minutes are there in an hour?一小时有多少分钟?(in an hour表泛指)
3 －What day is it todav?今天星期几/今天是什么节日?
－It is Tuesday/Children's Day，今天是星期二/儿童节。(It指Tuesday或Children's day，故Tuesday或Children'Day前不加on)
4 My birthday is on October 1st，10月1日是我的生日。(My birthdav前不加on)
5 Let's make it nine forty，我们把时间定在9:40吧。(it指nineforty，故nine forty前不加at)
6 It rained heavily last night，昨晚雨下得很大。(last night不能写成yesterday night)
7 We'll leave here tomorrow morning，明早我们将离开这里。(tomorrow morning不能写成next morning)
六、固定搭配。例：
in the morning／afternoon／evening；in the day=in the daytime；in themiddle of the day；in time；in no time；in the night；in a minute；in the21st century；in the past／last two years；in half an hour(在半小时之内／后)；in the end；in one's seventies：at noon；at breakfast／lunch／lunchtime，dinner；at night／midnight；at the weekend；at this time 0f day／year；at a bad time of year；at the/this／that moment；at first／last：at once；at thattime;at the end/beginning of；at the age of：at tlle same time；at times；on weekdays/holidays；on that day；on one's birthday；on time
温馨提示：答案为网友推荐，仅供参考