It means "What day is the birthday".
In what season/part of the year is (your) birthday
There is a party for you're Birth day
It means "On what month is Independence Day?"
Good day may God bless in this day
In what month is Thanksgiving Day?
It seems incomplete: as 'En que (mes/ano) es la (fecha) de tu cumpleanos', it would mean 'In what (month/year) is the (date) of your birthday?' The words in brackets are suggested possibilities.
It means "My birthday is in the month of".
On what day is your Spanish test?
CLARO QUE SI TONTA...CREO QUE TODOS CREEMOS EN SANTA ALGUN DIA QUE NO?
Que tengas un buen dia OR Que tengas buen dia = Both informal Que tenga un buen dia OR Que tenga buen dia = Both formal
EL DÍA EN QUE NACÍ.el dia que naci (Wrong spelling)
The translation is : Not a day goes by that I don't think of you.