I remember watching this movie as a kid, but can not for the life of me remember the title. It involves a kid who travels to another land through a grandfather clock, once in the world it is a race against time to same a princess maybe? There is a Dark stallion with Flaming red eye chasing the girl, dark animation, desolate setting. Any Ideas? This is driving me nuts!

Could it be 'The Last Unicorn'? Your description almost fit one of the last scenes...

That's what I was thinking, 'The Last Unicorn' fits

If it what I am thinking its not the last unicorn, does it have 2 young kids with a magic locket that when opened releases a rainbow?