How far in advance should I book train tickets from Paris to Bonn?

The best time to book your train from Paris to Bonn is <b>days before departure</b>. See how prices for trains change on the Paris to Bonn route.预订从巴黎至波恩的火车，最佳时机为出发日前数日。观察巴黎至波恩线路火车票价的变化情况。