The dinner is the part everyone remembers. The toasts, the table, the kid in the cap sitting across from family who flew in for the weekend. So the goal isn't just to pay for it — it's to set it up right, on time, without scrambling the week of. Reserve the restaurant space about three months out, send invitations six to eight weeks ahead, and lock the headcount two weeks before so you're not paying for empty seats or scrambling for extras.
A typical high school graduation dinner runs about $900 in the US once you add food, drinks, a small cake, and the private room fee. That's a real number, and it lands right when summer travel, dorm deposits, and moving costs are all hitting at once. The move is to give yourself a payment runway so the bill doesn't punch you in the same month as everything else.
Quick honest catch: 0% for 18 months means no interest for that window — it doesn't mean the dinner is free. If the balance is still on the card when month 18 ends, standard interest kicks in on whatever's left. So the plan only works if you actually pay it down on the schedule you set.