A law passed by the general assembly takes effect ninety days after the adjournment of the session at which it is enacted; but if the general assembly recesses for thirty days or more, it may prescribe by joint resolution that laws previously passed and not effective take effect ninety days from the beginning of the recess, subject to the following exceptions:

 (1)  A law necessary for the immediate preservation of the public peace, health or safety, which emergency is expressed in the body or preamble of the act and which is declared to be thus necessary by the general assembly, by a vote of two-thirds of its members elected to each house the vote to be taken by yeas and nays, and entered on the journal, or a law making an appropriation for the current expenses of the state government, for the maintenance of the state institutions or for the support of public schools, takes effect as of the hour and minute of its approval by the governor; which hour and minute may be endorsed by the governor on the bill at the time of its approval;

Terms Used In Missouri Laws 1.130

  • Appropriation: The provision of funds, through an annual appropriations act or a permanent law, for federal agencies to make payments out of the Treasury for specified purposes. The formal federal spending process consists of two sequential steps: authorization
  • following: when used by way of reference to any section of the statutes, mean the section next preceding or next following that in which the reference is made, unless some other section is expressly designated in the reference. See Missouri Laws 1.020
  • Joint resolution: A legislative measure which requires the approval of both chambers.
  • Recess: A temporary interruption of the legislative business.
  • State: when applied to any of the United States, includes the District of Columbia and the territories, and the words "United States" includes such district and territories. See Missouri Laws 1.020

 (2)  In case the general assembly, as to a law not of the character herein specified, provides that the law takes effect on a date in the future subsequent to the expiration of the period of ninety days herein mentioned the law takes effect on the date thus fixed by the general assembly;

 (3)  In case the general assembly provides that any law takes effect as provided in subdivision (1) of this section, the general assembly may provide in such law that the operative date of the law or parts of the law takes effect on a date subsequent to the effective date of the law.