If you have an original or reinvested security which has no reinvestments scheduled, you can request reinvestment of the security prior to its maturity. Go to ManageDirect and select the Schedule Reinvestments text link. To cancel or change the number of scheduled reinvestments for a security, select the Edit Reinvestments text link. You cannot schedule, edit, or cancel a reinvestment when the maturing security is in a closed book period, or when a noncompetitive bid for the replacement security is no longer accepted, whichever comes first. 对的，就是在下次的auction 之前，你可以随时撤销reinvest, 因为auction 之后，相当于你已经叫价了，就不可以撤销了。当然过了第二个term issue date后，你又可以撤销以后的
不懂， 这里的t+2是指？
是无缝的- 比如4星期的，每个星期二是issue day, 同时也是mature day。你可以选择reinvest，它就自动再投4星期。如果你让它mature的时候回到你的银行账户，你也可以用同一笔资金买mature 那天issue的bill，但是要在mature前的那个星期四之前（就是auction之前）下买单。
比如你买4 weeks的，自动reinvest两次，那为什么不买17周利率更高的呢？一种解释可能就是四周后mature 时候，你可以取出来
我理解是投资多次在一次到期时，可以撤回后面reinvest的选择，但买17周的没有任何撤回机会，不知对不对。
但是长的利率也高点
If you have an original or reinvested security which has no reinvestments scheduled, you can request reinvestment of the security prior to its maturity. Go to ManageDirect and select the Schedule Reinvestments text link. To cancel or change the number of scheduled reinvestments for a security, select the Edit Reinvestments text link. You cannot schedule, edit, or cancel a reinvestment when the maturing security is in a closed book period, or when a noncompetitive bid for the replacement security is no longer accepted, whichever comes first.
对的，就是在下次的auction 之前，你可以随时撤销reinvest, 因为auction 之后，相当于你已经叫价了，就不可以撤销了。当然过了第二个term issue date后，你又可以撤销以后的
就是到settlement需要2天
我又看了一下，t bill是当天settlement，其他bonds是2个business day