Calendar

Is there a single, generally accepted calendar (including time measurements), or do different countries or peoples or races have different ones?

How is the day divided into smaller time units? What are they (Hour of the Lark, Sunrise Bell, Nones, etc.)? Are the names relevant to anything? Is the length of an hour fixed, or does it vary depending on changes in the length of the day as the seasons change?

What are the names of months, and how many days in each? How many days in a week? Months in a year? Are there leap years? If so, who keeps track?

Which days are general holidays or festival times? What do they celebrate? Are there any that are only celebrated in particular countries, cities, or regions?

What event(s) do people use to date years? Do they use a single event (the creation of the world, the end of the Great War, the invention of atomic power, etc.) or are events dated based on recurring things (the 12th year of Tiberius’ reign, the 301st year of the Han Dynasty)?

How do people tell what time it is? Are there clocks, watches, sundials, etc., or do people have to just listen for bells from the castle or church, or just eyeball the sun?

Are there any days that are considered “outside the year,” like Mardi Gras or the Feast of Fools? How are these days customarily observed? How did they originate?