Locke, you're christian, right? Then, you should agree there must be places where time doesn't exist but those place(s) exist anyway?
''In the beginning'' in this sense is more a notion understandable for human heads rather than a concrete reality. Plus, the things don't work the same way for Goddesses than for us.
I agree with Komali. Though we could call it ''Triforce of Light'' instead of ''Triforce of Time'' and it would get more and more sense (even if I use to call it Triforce of Time too).
What if the Triforce breaks into 3 parts when you touch it because it is not solid?
What if the Triforce isn't solid because there's a big hole in the middle, making each of the triforces not to touch each other?
What if that hole once had / could have a piece in it, a ''Triforce of Light/Time'' or such?
And what if that part has been removed so both the Triforce would be fragile (so no evil can get it whole) and both to take the power of the Triforce of Light to a sword that can repel evil if ever evil finds the Triforce anyway?
What if that golden jewel on the Master Sword was that...Triforce of Time/Light?
We've all thought about that at least one time, I'm sure. And Nintendo knows it, I'm sure they know we'd see those details and make the links.