"I will see you in Friday morning" is not something a native English speaker would say (in USA). The others are all all correct. "on" is optional in this phrase in modern English. Note that "I will see you in the morning" is perfectly fine, but we do not say "in Friday morning."

Mike is correct on all counts. Why say "on" and not "in"? In general, "in" is used for open-ended periods of time, whereas "on" is for more specific periods. "In the evening" is correct, as in "on Friday". "We will schedule the meeting in July, probably on July 23rd".

其实 today 加不加on都行， 不加on 表示泛指，today 此时是副词： 加上on后 强调是在今天这个特定的时间，today 又变成了 名词 ：）