This small and densely populated city of about one million is in the northwest part of Argentina, so it can get pretty hot and humid at times. So much so that it long ago adopted a "siesta" routine throughout the year. That means that shops and schools open in the morning and shut down around noon, then reopen from about 4 to 8 pm, because the midday heat can be intolerable. That in turn means that most people end up commuting four times a day. It's terribly inefficient.
There's a rush hour in the morning as cars, buses, bicycles and motor scooters flood into the city in the morning, then another rush hour from noon to 1 pm as they all head back home for lunch. Families get together for lunch from 1 pm to 2:30 pm, which is very nice for family unity, and then the parents take a nap before those who have to work head back to the office around 4 pm. Then everyone migrates back to their homes around 8-9 pm. Dinner is usually light, and often doesn't get started until 10 pm.
Since we have a lot of friends and family here, we have invitations for lunch and dinner every day. Lunch from 1:30 to 3:30 pm, then back to the hotel for a nap, then meet friends for coffee and do some errands in the city. We were invited to dinner last night at 10 pm, but got there a bit late since it's always hard to disentangle oneself from a gaggle of friends at the coffee shop, and the rush hour traffic was worse than we thought. Dinner and conversation lingered until after 2 am, at which time our host drove us back to the hotel. We got to bed around 3 am, and he probably had to get up at 7 am to go to his office.
We got up at 10 am this morning, and today for the first time we'll have a chance to have some breakfast downstairs before running some more errands before shops close and then going to a friend's house for lunch. Since Tuesday is a holiday (to honor the victims of the military takeover in 1976—which seems strange to me because we were living here at the time and everyone rejoiced when the military took over and then began to rid the country of the leftist guerrillas that were planting bombs everwhere and sowing anarchy), some friends are having a huge party Monday night to celebrate their wedding anniversary and milestone birthdays. The party starts officially at 10 pm, but most people probably won't arrive until 11 pm. Then dinner might get underway at midnight, followed by dancing and conversation that could last until breakfast. Finishing off a big party with breakfast is a sign of a successful party. I should know, because we threw a similar party for ourselves some years ago, and breakfast was part of the planning process.