When I younger, I watched an animated movie about a princess or a girl of some importance who has an enchanted necklace that will gain all its power on the eve of her 18th birthday. She is kidnapped by an evil enchantress (pretty sure it's a woman) who captures her and forces her to drink a potion so that she can gain the power of the necklace. To force the girl to drink the potion, she threatens the life of a young boy who has set out to save her. I remember details like, the girl falls down a slide into a caged caravan before drinking the potion. The boys must follow a clue and find a place where night meets day (which turns out to be through a path in a giant hedge). If anyone can help me it would be greatly appreciated, my life will not be complete until I figure out what this movie is

I believe it is "once upon a time"