Which Mexican states still observe Daylight Saving Time?

In October 2022, most of Mexico ended Daylight Saving Time (DST) after the Senate passed a bill to eliminate biannual clock changes. However, according to the current Time Zone Law, 33 municipalities that share a border with the United States still observe DST.

On Sunday, March 10, the following municipalities will set their clocks forward one hour at 2 a.m:

• Chihuahua: Ciudad Juárez, Ojinaga, Ascensión, Coyame del Sotol, Guadalupe, Janos.
• Coahuila: Acuña, Allende, Guerrero, Hidalgo, Jiménez, Morelos, Nava.
• Tamaulipas: Nuevo Laredo, Guerrero, Mier, Miguel Alemán, Camargo.
• Nuevo León: Anáhuac.
• Baja California: Tijuana, Mexicali, Ensenada, Playas de Rosarito, Tecate and San Quintín.

Daylight saving time was adopted nationwide in 1996 with the idea of using more natural light and less electricity for lighting buildings, as well as facilitating commerce with the U.S.. However, the arguments in Mexico to keep it nationwide were not strong enough for those who wanted it repealed. Northern border cities, however, were allowed to keep DST in order to continue encouraging U.S.-Mexico trade.

During the discussion to approve the new law, the head of the Senate Energy Commission Rocío Abreu Artiñano, noted that energy savings from using DST had been less than 1% of the total energy consumed each year. 

However, a study conducted by the National Institute of Electricity and Clean Energy (INEEL), reported that the implementation of DST in 2006 resulted in the prevention of 1,427 tonnes of carbon dioxide emissions into the atmosphere and a reduction of 2,754 million barrels of oil in fuel consumption for the generation of electrical energy.

The use of DST is a controversial topic worldwide. Over 140 countries have implemented it at some point but approximately half have since abolished it. 

As day length variations are minimal around the equator, most tropical regions do not change their clocks. Currently, less than 40% of countries in the world observe DST. 

With reports from El País and El Financiero