it's ...'s birthday
La semana que viene es el cumpleaños de Tom.
Next week is Tom’s birthday.
Pasado mañana es el cumpleaños de Tom.
The day after tomorrow is Tom's birthday.
It's my daughter's birthday.
It's my father's birthday.
No te olvides de que mañana es el cumpleaños de Tom.
Don't forget that tomorrow is Tom's birthday.
It's my son's birthday.
Es el cumpleaños de tu madre, podrías quedarte.
It's your mother's birthday; you could stay.
— El médico de Budapest (2020)