Mi cumpleaños es este jueves. Note the days of the week are not capitalized in Spanish.
"Mi cumpleaños". That is how you say "my birthday".
I have to work Thursday is "Tengo que trabajar el jueves."
"Thursday" in Spanish is "jueves". It is not capitalized.
"when is my birthday" translates to "cuando es mi cumpleaños" in Spanish.
cumpleanos
cumpleanos
Mi cumpleaños es (your birthday)
¿Quieres salir conmigo el jueves
Cuando(when) es(its) tu(your) cumpleaños(birthday).
it's his birthday - "es su cumpleanos"
regalos
Jueves de agosto el vigesimo