how to say birthday in spanish?
when is your birthday?my birthday is in the month of january.
4 Answers
Please don't forget to use proper capitalization in your posts...January, Julio, July
I thought that months in Spanish, like days of the week, were lower case.

We use too 'aniversario'(anniversary), but these word can be used in other context:'Nuestro aniversario de bodas es en el mes de enero' (Our wedding anniversary is in the January month). 'El aniversario de USA es el 4 de julio' (The USA anniversary is 4th of July).
The word 'aniversario' can be used to things.
Excuse me, but in spanish the name of the months don't use capitalization...
In english you use?
The word for "birthday" in Spanish is "cumpleaños".
So your sentences would read:
¿Cuando es tu cumpleaños? El mío es en el mes de enero.
My birthday is in December.
Yo cumplo años en diciembre.