The Cry of Dolores is a historical event that occurred in Dolores, Mexico, in the early morning of 16 September 1810. Roman Catholic priest Miguel Hidalgo y Costilla rang the bell of his church and gave the pronunciamiento that triggered the Mexican War of Independence. Wikipedia}

     September 15 – Cry of Dolores –  (El Grito de la Independencia) in the town of DoloresThe Cry of Dolores (Spanish: Grito de Dolores) is a historical event that occurred in Dolores (now Dolores Hidalgo), Mexico, in the early morning of 16 September 1810. Roman Catholic priest Miguel Hidalgo y Costilla rang the bell of his church and gave the pronunciamiento (call to arms) that triggered the Mexican War of Independence.Every year on the eve of Independence Day, the President of Mexico re-enacts the Grito from the balcony of the National Palace in Mexico City, while ringing the same bell Hidalgo used in 1810.

     September 16 – 
Mexico’s independence from Spain is celebrated every year on September 16 to commemorate the beginning of the Mexican War of Independence in 1810. However, Mexican patriotic spirit is embodied in a multitude of popular traditions celebrated over the months of September and October.
From the beginning of the September, Mexico’s streets and buildings are festooned with an explosion of green, white, and red, but the main events occur when crowds gather in town squares across the nation to shout “Viva México!” on the evening of September 15, and again on September 16, when you’ll find parades and other civic celebrations.
Some people outside of Mexico may confuse Mexican Independence Day with Cinco de Mayo (May 5), but that is a different celebration (and a much less important one in Mexico) that commemorates Mexico’s victory over France at the Battle of Puebla in 1862 during the Franco-Mexican War.
Mexican Independence Day, on the other hand, is a celebration of the start of the Mexican War of Independence and is also referred to in Mexico by the date of the event: el dieciséis de Septiembre (the 16th of September). 
It is one of Las Fiestas Patrias (the patriotic festivals) and is celebrated on the night of September 15 and all day on September 16 each year in cities across Latin America.
This is one of the most important fiestas of the year in Mexico, and the whole month of September is referred to as el mes de la patria (month of the homeland).