It very much depends on how this spell is rated, if it has at least 4 stars you have a good starting point but also this is not enough to prove that it could work in dependent upon the conditions of which the time of the spell is to be performed.
Don't go with the star rating, there's a reason for everything. The spell requires this moon phase because whoever wrote it works with the influence of the moon as do many casters. The moon pushes and pulls energy, so casting with this natural influence can help your spell. Think of it like swimming, when it's with the current it's quick and easy, against, while possible, is more difficult.