Antelación/anticipación

[AngelicaDeAlquezar]

I've just realised I'm not sure about how to translate the next sentence:

¿Con cuánto tiempo de antelación/anticipación necesitas saberlo?

I've ventured:
·How long in advance do you need to know?
·How long beforehand do you need to know?

Are these sentences grammatically correct? In case they are, are they an immediate choice for native speakers or is there a more natural way to say this?

All help, as always, will be highly appreciated.

[Rusty]

Both work. The first sentence would be more commonly heard, especially with 'in advance' tacked onto the end of the sentence.

How long do you need to know in advance?
How long in advance do you need to know?
How long do you need to know beforehand?

[AngelicaDeAlquezar]

Ah, the place of adverbs... I seem to always have trouble with that.

Thank you, Rusty!

[Rusty]

Another thought.

'How far in advance' is much more popular, and the 'in advance' part isn't separated. That's the best choice.
You can use 'far' with 'beforehand', but 'long' sounds better.

[AngelicaDeAlquezar]

Wow! Useful!
Thank you again! Tricky parts of languages are so much fun!

[Perikles]

Originally Posted by Rusty

How long do you need to know in advance?
How long in advance do you need to know?
How long do you need to know beforehand?

I can't improve on the above, but there is also the possibility of

How much notice do you need?

I think this is what I would automatically say, but might be colloquial.

[AngelicaDeAlquezar]

Thank you, Perikles, I'll learn this one too.