Mon anniversaire est la (un, duex, trois, etc...) and then a month for example August, Janvier, Avril, Decembre, Novembre, etc....
a birthday is 'un anniversaire' in French
Birthday is "anniversaire" (masc.) in French.
You say it exactly the same, but spell it as 'Mai'
d'anniversaire
Either may be correct depending on context. If you are merely specifying the month then it would be correct to say your birthday is in that month. Being more specific you would say your birthday is on a specific date.
A birthday cake in French is 'un gâteau d'anniversaire'
you say mon gorna be mansa
In French, you would say "Quel est le mois ?" to ask "What is the month?"
un anniversaire
"Today is my birthday!" in French is "Aujourd'hui est mon anniversaire !"
Juillet
you say "son anniversaire"