MEXICO CITY (AP) -- Mexico City is being ordered to fall back to the national
                  line on springing ahead.

                  The Supreme Court on Friday ruled the capital city doesn't have the right to
                  refuse to switch to daylight-saving time with the rest of the country in May.

                  While the decision may not be the last word, it was a victory for President
                  Vicente Fox's attempt to keep the country on the same clock.

                  The debate was launched early this year when Mexico City's mayor, Andres
                  Manuel Lopez Obrador, proposed a referendum on doing away with daylight
                  time.

                  Lopez Obrador, a possible presidential candidate in 2006, had called daylight time
                  a symbol of an overly powerful executive branch, saying Fox "does not have the
                  power to change the hour" across the country.

                  The leftist mayor decreed that Mexico City would simply refuse to spring ahead
                  -- even if the federal government ordered schools, hospitals, airports and banks
                  within the capital to operate an hour ahead, creating two different time zones
                  within the city.

                  Imported in 1996 from the United States, the time change -- ahead one hour in
                  the spring, then back again in the fall -- has yet to win the hearts and minds of
                  Mexicans. Many feel it disrupts their biological clocks. Others complain that it is
                  difficult to get their children up in the dark of the morning or to put them to bed
                  when it's still light out.

                  Others simply ignore it.

                  "That's government time. We have our own clock here," Mije Indian Leandro
                  Perez, in the Oaxaca mountain town of Mixistlan, said recently.

                  Other states in Mexico also want to adjust the clock to their taste, saying they
                  will have five months of daylight time, some six, some seven.

                  Federal officials argue that daylight time saves hundreds of millions of dollars in
                  energy costs and helps coordinate Mexico's companies with their main trading
                  partners in the United States.

                  They also say that leaving Mexico City behind an hour would create mass
                  confusion among tourists flying into the capital and workers arriving from
                  suburbs.

                  In its ruling Friday, the Supreme Court argued that Lopez Obrador's decision not
                  to follow daylight time would have national and international repercussions,
                  hurting the economy and disrupting the lives of Mexico City's residents,
                  Mexico's state-run Notimex news agency reported.

                  But the court decision wasn't the last word on the subject. The court said it plans
                  to study the issue further and could issue more rulings on its constitutionality.

                  Fox was in Colombia on Friday, but his National Action Party expressed
                  satisfaction with the ruling, saying it "guaranteed the stability that Mexico City
                  needs to fight arbitrary acts like the one decreed by Andres Manuel Lopez
                  Obrador."

                  "This ruling should serve as a lesson to Mexico City's government, which has
                  spent the large majority of its time systematically attacking the president,"
                  Notimex quoted the party as saying in a statement.

                  Lopez Obrador said he wasn't giving up, adding that the court's ruling wasn't the
                  "definitive result."

                  Copyright 2001 The Associated Press.