Barcelona: la merci fiesta?

hi all,
I'm planning to come to Spain for a holiday by 18-Sept. I want to see the firework for the la merci festival (around 24-Sept). Can anyone tell me when is the firework happening? on the 24th? I tried to search on some link but can't find the info / date. thanks very much.

I am not very sure but I think you're speaking of La Mercé (La Merçé in Catalonian).

But I just don't know when the fireworks are.