Votre commentaire: "See above the definition of 'créneau'"
Yes, please! Do so:
http://www.cnrtl.fr/definition/créneauThen, read the whole 2 liners in the question box and try to make sense of it.
Forget the idea that this is about a "calendar" - especially since they talk about "capacity options".
Make the link between "we have some capacity options to discuss" and "their position on Villeret Capacity".
Help yourself with Caroline's Bajwel's answer.
Now, try to make sens of "créneau" in such a context and PLEASE, come to the conclusion that it doesn't fit in.