Article 66 Political Constitution of the United Mexican States
Third Title · Chapter II. On the Legislative Power · Section I. On the Election and Installation of the Congress
Current text · last reform published in the Official Gazette of the Federation (DOF) on 2 June 2026
Each period of ordinary sessions shall last the time necessary to deal with all the matters mentioned in the preceding article. The first period may not be prolonged except until 15 December of the same year, except when the President of the Republic begins his office on the date provided for by Article 83, in which case the sessions may be extended until 31 December of that same year. The second period may not be prolonged beyond 30 April of the same year.
If the two Chambers are not in agreement to put an end to the Sessions before the indicated dates, the President of the Republic shall resolve.