How late is it polite to arrive to a dinner in Spain or Latin America?

The rule in one sentence

what

The time on a social invitation is not the time of arrival: it is the time from which one may arrive. Arrive at eight sharp and you may find your host in slippers.

when

At a family meal the margin is wide; at a dinner in a restaurant it is much narrower. A reasonable margin runs from twenty minutes to an hour.

where

Across the Spanish-speaking world, with differences by country and city. The piece makes its joke work from Madrid to Managua.

who

Hosts and guests who know the system. It is perfectly clear to those who use it, and only confusing from outside.

why

Closeness — confianza — sets the margin. The two clocks, social and professional, coexist in the same person without difficulty.

• The time of an invitation is not the time of arrival but the time from which one may arrive.
• The reasonable margin runs from twenty minutes to an hour, depending on the country, the city and how close you are; wide at a family meal, much narrower at a restaurant dinner.
• The system is clear to those who use it and only confusing from outside.

La hora de una invitación no es la hora de llegada: es la hora a partir de la cual se puede llegar.

The time of an invitation is not the time of arrival: it is the time from which one may arrive.

El margen razonable va de veinte minutos a una hora, según el país, la ciudad y la confianza.

The reasonable margin runs from twenty minutes to an hour, depending on the country, the city and how close you are.

En una comida familiar el margen es amplio; en una cena en un restaurante, mucho menor.

At a family meal the margin is wide; at a dinner in a restaurant, much narrower.