During a debate in the U.S. Senate, either once cloture has been invoked or if the Senate is operating under a unanimous consent agreement, a senator can only speak if another senator yields time. Generally, the only senators who can yield time are the floor managers for the bill. However, there are times when a senator who has been given the opportunity to speak can yield time to another senator, if the time has not been used in its entirety.
In order to yield time, a senator declares he or she is yielding time to the Senate president. At that point, the senator can then yield time to any senator he chooses. In most cases, this would likely be a senator who is willing to bolster the argument of the yielding senator.
There are a number of situations in which a senator could feel compelled to yield time. Sometimes, a senator may yield time simply because he wishes to have a question answered. In other cases, a senator could yield time simply because other business needs to be taken up. A senator can also yield time in order to allow another senator to make a statement. In this last case, a senator cannot reclaim the time he or she yields.
However, a senator who receives time in order to make a statement is not required to use all that time. In those cases, a senator may yield time back to the floor manager, or yield to another senator. Usually, the senator yields his or her time back to the senator who initially granted him or her permission to speak.
In addition to the unanimous consent agreement rules, yielding time can also be important when cloture is invoked. Cloture limits the overall debate to 30 hours and no senator can talk for more than one hour. However, if a senator does not use his or her time, that senator can yield time to another senator, which is usually yielded to the floor manager or party leader in their respective political party. At that point, the senator receiving the time can use it to present remarks, or pass all or a portion of it to another senator.