My uncle is coming to my home the day after tomorrow.这个句子是对的
确切的日期,几月几号,星期几,之类的时间名词前加 on;
确切的时刻,几点几分之类的时间名词前加 at; 以及at night;
固定短语中,in the morning/afternoon/evening 中用 in；
但是 today,tomorrow,yesterday,the day before yestery,the day after tomorrow,tonight,next(week/month/year/星期几等),last (week/month/year/星期几等),this（morning/afternoon/evening 等） ,之前不用介词