A quinceañera is a big moment that pulls in a lot of moving parts. Planning 12 to 18 months out gives you the breathing room to secure venues and vendors before prices climb.
Big events hit the wallet all at once, so your main goal is spreading that $12,000 cost out so it doesn't sink your monthly budget. Break down your milestones early so you know exactly what is due and when.
Remember that the 0% window is a deadline, not a gift. If you have a balance left when the 18 months are up, the interest rate will jump significantly, so aim to clear the total before that clock runs out.