Did you know?
Mexican business hours in the cities are 9:00 a.m. until perhaps 6:00 p.m. Governement offices may be open much later, until 9:00 p.m. or more. Lunch is often a key business venue that extends from about 1:30 p.m. to 3:00 p.m. Senior government people can begin lunch as late as 4:30 p.m.
Here is a great site for cultural etiquette. Although focused on the business world, it is also very helpful for general cultural understanding for about 4 dozen countries.