Which city was the capital of the aztec civilization

So the Aztecs had a capital city Tenochtitlan. They decided to build their capital in a swamp. Clearly they had some major architectural and engineering achievements to build their capital city in a swamp.

answer: the time zones used to be whatever the local authority wanted them to be. one town might have 6am whenever the sun came up and another town had 6am 10 minutes later.  

the trains had a hard time when their orders said to be at a certain point at 6am.  

6am, but who's 6am.  

the railroads got together and set the time zones more or less along the longitude lines across the country.

explanation: