Calendar numbers have no bearing on when a measure will be called up for floor debate and votes. They merely indicate the order in which the measure was received. Bills and resolutions get calendar numbers in the order they are placed on the calendar, usually immediately after a committee has reported the measure to the floor. However, sometimes bills are placed on the calendar directly after introduction, using a special procedure under Senate Rule XIV.

The Senate's web-site has a feature which provides a match between bill numbers and calendar numbers. Go to "www.senate.gov" then click on "Legislative Activities." Choose "Senate Legislative Calendar" and finally, click on "Cross Index of Measures to General Order Numbers."

The Senate Majority Leader decides when a bill or resolution will be brought up for floor consideration based on political factors, not because of any automatic procedure. He can only bring measures up by getting unanimous consent to do so, or by moving to proceed to a specific bill. The motion to proceed is a tempting target for a filibuster since debate on it is without limitation. As a result, the Majority Leader attempts more often to call bills up only after negotiating an agreement with the other side. Leaving bills on the calendar until political clearance is obtained, no matter how long the negotiating process, saves more time in the end.