Thanks Reene, it contains even more info than what I expected! Indeed, I can change not only the ending date but could even the speed: I am considering an extra quick speed. Unless someone knows about a super quick speed somebody already created...? Actually, there are quite many parameters to change for a new speed and they need to be balanced.
Actually, the point in having a speed higher than quick is that already the quick speed might take me 25h... (Is it normal?)
Thanks,
Ulysse