here's a logic question if you wanna take a break from studying and kill more brain cells. haha... question courtesy of jy...

John and David have a tuition teacher, Victor.Victor told John his birth month and told David his birth day. He listed his possible birth dates.

4th March, 5th March, 8th March
4th June, 7th June
1st September, 5th September
1st December, 2nd December, 8th December

John said, "I do not know, and so, neither does David"
David said, "I didn't know at first, but I do now"
John said, "Oh, I know now too"

What is the birthday of Victor?

answers anyone?