The treasury bills, popularly known as T-bills, are the type of government debentures used to generate public money in the form of debt. These are the risk free area of investment with a reasonable money growth. Every government issues T-bills, but the circumstantial conditions and rate of returns depend upon the issuing government.The U.S. Distributes them through the Bureau of the Public Debt of the Department of Treasury in the form of treasury securities, or simply Treasuries. In the US, there are four kinds of Treasuries. Other three types are Treasury notes, Treasury bonds, and Savings bonds. The T-bills are sold on each Friday through auctions held on each Wednesday at noon, for a maturity period of one year or less. For purchasing treasury bills, requisite auction orders are to be entered in the United States Treasury's website www.treasurydirect.gov before 11:30 on Monday. This type of debenture does not yield any interest before maturity similar to the zero-coupon bonds. To give a boost to the selling and attract public interests, the treasury bills are sold at a discount rate of the par value. In U.S., treasury bills are usually available for the maturity period of 28 days (~1 month), 91 days (~3 months), and 182 days (~6 months). Mature T-bills can be enchased on every Thursday.