This sounds familiar but I'm having trouble placing it. Do you have any other details? (If you know the answers to any of these questions, it might help.)
— Season? Pre- or Post-Gift?
— "Time doesn't progress" — So it stays the same time thru the fic? Is it day or night?
— What are the Scoobies & everyone doing while frozen? Are they in bed or going about their day?
— Is it possibly unfinished or do you remember reading all the way to the end?
As I'm talking this through I remembered what I thought it may be (but I think I'm wrong now), so last question — it isn't Dust, by KnifeEdge
If not, any more detail would be great!