Thank you very much all.
HD, Band, of course I will ask my (future) employer - just want to have my homework done before that, so when they tell me that the days are to be calculated this or that way, at least I know in advance how is done elsewhere. I think it's better to be prepared than to simply pop up there and ask without any further background.
You are right, it will depend on how FerroN wants to do it - hopefully it will be the same way as you are saying here, but just wanted to know which was the NATS way before speaking to FerroN, to at least be able to know if what they say is or isn't "fair"...
Guys, thanks again, this has been very useful!