Hi Princess Emma, go to the website you tried before - I can see you have got part of a ticker pasted into the top of your avatar (you see where I have Sorceror Mickey & you have Ariel? Those are avatarsr). Your code is just above those.
Anyway, go back to the website (such as www.tickerfactory.com ) and create your countdown by following the instructions, then copy the code you are given at the end, then come back to the Dis.
Go into "User CP" which is in the top left hand of your screen. Then go into "Edit signature". There will be a box which is in effect your "signature". Paste the code you copied from the ticker website in there, save changes and away you go!