The shortest term debt instrument in the United States is the Federal Funds Rate, which is an overnight rate--one day maturity-- and the longest issued by the Government is a thirty-year government bond, which will be repaid three decades in the future.

美国最短期的债券,是联邦基金利率,隔夜拆兑,一天到期,而时间最长的国债,是一种三十年期的政府债券,未来三十年才兑现

耶鲁公开课 - 金融市场课程节选