Its supposed to be if you bd the day of ovulation that you have a better chance of a boy since boy sperm have shorter lives but move faster than girl sperm. But unless you get a fertility treatment there is no way to 100% get a boy. I bd during ovulation and now I have a darling daughter.
I personally dont think it is possible, but perhaps it is. I have been trying to work out when i am most fertile (my periods are irregular) so i can AVOID those days lol
I found conception calculators but there was one called the Jonas Method. It told you to input your birthdate and time of birth to work out which lunar phase you were born in.
So for me it said if i was to conceive on 7th Sep 08 i would conceive a boy.
No idea if its true as im not planning for that anytime soon but it could be worth a look.
Good luck