Yes, it is. Most months, you can buy binds up to the 27th or 28th. Bonds are also redeemable on the first day of the six month. Therefore, youonly hold the bond for 5 months and a couple of days.

Add to that the float on your credit card, which can be as much as 50 days, and the time your money is tied up in th bonds is 4.5 months.