June 4, June 7

September1September 5

65438+February165438+February 2nd 65438+February 8th

Xiao Ming said: If I don't know, Xiao Qiang certainly doesn't know. That is to say, his month is March or September. Because if there are two other months, you can know your birthday without knowing the month.

Xiao Qiang said: I didn't know at first, but now I know. This sentence means that his date is not 5. Because, two months exist on the 5th.

Xiao Ming said: Oh, I know. This means that after excluding 5, there are only 1 possibilities left. So it is September 1.