Senate Rule XXII, however, known as the cloture rule, enables Senators to end a filibuster on any debatable matter the Senate is considering. Sixteen Senators initiate this process by presenting a motion to end the debate. In most circumstances, the Senate does not vote on this cloture motion until the second day of session after the motion is made. Then, it requires the votes of at least three-fifths of all Senators (normally 60 votes) to invoke cloture. (Invoking cloture on a proposal to amend the Senate’s standing rules requires the support of two-thirds of the Senators present and voting, whereas cloture on nominations requires a numerical majority.) The primary effect of invoking cloture on most questions is to impose a maximum of 30 additional hours for considering that question. This 30-hour period for consideration encompasses all time consumed by roll call votes, quorum calls, and other actions, as well as the time used for debate.