Under the Senate's rules, the Senate must have a period for morning business every day to allow Senators to introduce bills and resolutions. Technically, morning business should occur in the first hour after the Senate convenes at the start of a new legislative day. In practice, Senate leaders ask unanimous consent to set aside the regular order and institute a period for morning business in bits and pieces throughout the day, as is convenient.

Morning business in the Senate means routine business, defined as the introduction of legislation, the filing of committee reports, the receipt of messages from the House or the President, the presentation and referral to committee of petitions from individual citizens and memorials from state legislatures, and, if unanimous consent is granted, 5-minute speeches on any subject to which a Senator wishes to speak. Most often Senators associate the term "morning business" with the 5-minute speeches. This is because most of the remaining routine business mentioned takes place automatically, without mention on the Senate floor.

When morning business does occur in the morning, it comes after "leader time," the time reserved for the Majority and Minority Leader at the start of the day. Thereafter, the leaders may use morning business when they need to fill up time in the intervals between bills, or to suit the schedule of a specific Senator who wishes to make a floor statement not related to the bill pending on the floor.

In daily practice, the duration of the morning business period on any given day varies widely, ranging from a few minutes to an hour or more.