Geography, Countries, and Culture

The world is flat. It looks like this:

               

Roman Empire

The Roman Empire is located in the continents corresponding to Europe, northern Africa, western Asia, and North America. Specifically, it contains Brittania, which contains Londinium. The language is called Latin, but is in fact almost identical to Earth English. The leader of the Empire is called Caesar (formerly "Emperor", but it was renamed when it was first held by a woman).

The Empire uses metal coins for money. A gold is eight silver, a silver is eight copper and is allegedly kept at about a basic day's wage but is in practice usually a bit higher, coppers can be physically broken in eight and also are tied to a fluctuating number of black pieces so that inflation can happen.

Slavery exists. People become slaves via the Empire conquering new places, debt, parents selling their children, and being born to slave parents. Power plants are run almost entirely by slaves, supposedly because it's easier to teach the relevant skills to children who don't learn other things.

Jesus is a currently-alive spiritual leader and activist. He is planning to maybe get very publicly executed by the Empire as something adjacent to a publicity stunt.

Corporal punishment is common in the judicial system.

Arbiters are a group of seasonchanges who are really dedicated to providing impartial judgments on things.

Association of Realitists Republican Empire

Is having a Cold War with the Roman Empire. Contains the parts of Asia not covered by the Roman Empire, including the Indian subcontinent. Speaks Surran. A board game tournament that features one competitor from each of the two empires is extremely interesting to the media, in a way remarkably reminiscent of the (Earth) musical Chess.

Pacifis

Australia. Was underwater for a few strong years before the stars made it resurface, at which point it became home to a culture which dedicates itself to philosophy.

Archipeligo

An alliance of various islands and also various non-islands, which has a few base rules and otherwise lets its member nations set their own laws. One of the member nations is known for its tourism industry and its weird rivalry between surfers and bikers. Another has a ton of winter solstices living there even though they don't especially involve themselves in the government. Archipeligo has five or six dominant languages that most people speak at least one of.

Verona

A country by the Great Lakes, surrounded by Rome. Ambiguously part of the Archipeligo, depending on who you ask. Run by New Year's gemini. Anyone who physically gets there can stay, no questions asked. The downside is that sometimes one of the New Year's gemini will take a liking to you and drug you and keep you as a sex slave, for example.

Other World Languages

Esperanto is is locally called Paroleblo and is not a conlang. Several other languages are combinations of some Earth languages. 

General Culture

Homosexuality is viewed as an odd person thing, and two even people being gay together is seen as unnatural.

Since days are longer, people tend to have vocations, hobbies they are sufficiently devoted to that they are basically second jobs.

The Alphabet Conglomerate is a group coordinating various activist and charitable organizations to optimize for the most good being done. Jesus is associated with them in some capacity.

Astrology is the study of the stars' supernatural effects, including birthdays. (Astronomy, by contrast, studies the stars as physical phenomena.) Before astrology was a rigorous science, people had noticed some trends in babies born on specific days or seasons, but some of these trends were just superstition and do not actually correspond to reality.

Eugeminics is doing eugenics to select for desirable birthdays. Soft eugeminics is done via soft incentives or attempts to convince, as opposed to hard eugeminics, which is done by force, usually by law (eg by not allowing some birthdays to enter a country). Flat eugeminics is about preventing or encouraging births on certain days, and sharp eugeminics is about acting on people who already exist (eg by murder). 

Some people believe that any degree of aiming to get a better birthday for your child is wrong, and try to randomize when the child is conceived or even hide somewhere in a cave for a while to lose track of what day it is before conception. Other people believe you should do extensive research and pick the very best day specifically for yourself and your partner. Still other people believe the distribution of birthdays should be as even as possible, even though the One has not said it is necessary, and try to aim for the uncommon birthdays.