A matter of time

A matter of time
 

En inglés decimos: no es una pregunta de si sino una pregunta de cuando
es a matter of time.
It's not a matter of if, it's a matter of when. It's just a matter of time.

It's just a matter of time = Es solo cuestión de tiempo

Oh!, the obvious. Thanks.

agree. Es solo cuestión de tiempo/Es solo una cuestión de tiempo
Saludos :D

I agree with "cuestión de tiempo" for "a matter of time".
However, "it's not a matter of if, it's a matter of when" is tougher to translate, as "no es cuestión de si, sino de cuándo" wouldn't be easily understood.
I'd say something like "no se trata de si va a pasar, sino de cuándo va a pasar".

It's doesn't matter when?

I can say too.

I don't care when?

Is it right the second phrase?