Calendars (The Expanse)

Calendars are a way of measuring days, years and seasons. In Scenario: The Expanse several calendars are used. When on this page it says “The calendar started on ...” that is not the date it was created, but the date of year and day 0 (or 1) in said calendar.

Gregorian calendars
Gregorian calendars are calendars that use the same way of keeping track of time as the Gregorian calendar.

Gregorian calendar
The Gregorian calendar, sometimes called the colloquial calendar, is the most commonly used calendar on Terra, rotating habitats and asteroid bases. The calendar was created by Christopher Clavius, implemented and named after Pope Gregory XIII. The calendar starts on the first of January of the supposed birth year of Jesus Christ. According to this calendar we are currently in the year 3463. The calendar starts the year on January 1st and ends it on the 31st of December. The year is split into 12 months: January (31 days), February (28 days, 29 in leap years), March (31 days), April (30 days), May (31 days), June (30 days), July (31 days), August (31 days), September (30 days), October (31 days), November (30 days) and December (31 days). The year is 365 days long and split into weeks, every week is 7 days long (Monday, Tuesday, Wednesday, Thursday, Friday, Saturday and Sunday). The Gregorian calendars has 1 complication: leap years. The year is not exactly 365 or 366 days long but is actually 365 days, 5 hours, 48 minutes and 45 seconds (and 138 milliseconds) long, so in order to stop the calendar from falling out of sync with the seasons every 4 years an extra day is added to February, called the leap day. This however is still not exact and causes the calendar to slowly fall out of sync so if the year is divisible by 100 than the leap year is skipped. This is still not percise and therefore if the year is divisible by 400 it is still a leap year. This was the original Gregorian calendar for hundreds of years before in the year 2756 the Parker Adjustment was added, the Parker Adjustment was a small extra complication to the Gregorian calendar, the year 2800 would normally be a leap year, but the according to the Parker Adjustment it was not. This adjustment makes it so that if a year ends on -2800, -5600 or -8400 it is not a leap year, this still is not exact but it will cause the calendar to fall out of sync by 1 day every 91,743 years.

Holocene calendar
The Holocene calendar, sometimes called the scientific calendar, is the main calendar used by the scientific community. The only difference between the Holocene and the Gregorian calendar is its starting date, while the Gregorian calendar starts with the birth of Jesus Christ, the Holocene calendar starts on January the first 10,000 BCE (in the Gregorian calendar) at the year the first temple of humanity was constructed. According to this calendar we are currently in the year 13,463.

Homo Sapiens Sapiens and Homo Genus calendars
The Homo Sapiens Sapiens, more often called the Human calendar and the Homo Genus calendar are both versions of the Gregorian calendar that start way earlier, the Homo Sapiens Sapiens calendar starts in the year 200,000 BCE, the supposed time that Homo Sapiens Sapiens evolved, according to this calendar we are currently in the year 203,463. The Homo Genus calendar starts even earlier, it starts at the supposed time the Homo Genus first evolved, 7 million BCE, according to this calendar we are currently in the year 7,003,463. Both of these calendars were created more as a joke than as an actual proposal and neither are used by any group of people, not even the creators use them.

Mayan calendar
The Mayan calendar was created by the Maya on Terra. The calendar was not used by anyone after the fall of the Maya up untill in 2024 the Spirit Science cult was formed and decided to honor the Maya by using their calendar. The calendar started on the 6th of september 3114 BCE. The calendar works completely differently from any other calendar. It is split into cycles, each with its own name. The k’in was 1 day long, 20 k’ins form a winal (sometimes also spelled uinal), 18 winals form a tun (360 days). 20 tuns make 1 k’atun (7200 days or about 20 years), 20 k'atuns make a b’ak’tun (144,000 days or 394 and a quarter years). These are the main units but there are several ones that go even higher: a piktun, which is 20 b'ak'tuns (2,880,000 days), 20 piktuns is 1 kalabtun (57,600,000 days), 20 kalabtuns form 1 k'inchiltun (1,152,000,000 days) and finally 20 k’inchiltuns form a single alautun (23,040,000,000 days or over 63 million years). The date is written in a simple way: [number of b’ak’tun].[number of k’atun].[number of tun].[number of winal].[number of k’in], for example in the date 12.17.15.17.1 the 12 is the amount of b’ak’tun, the first 17 the amount of k’atun, 15 the number of tun, the second 17 the number of winal and the 1 the amount of k’in since the 6th of September 3114 BCE, or in the Gregorian calendar the 21st of July 1969, the day the first man set foot on Luna. According to this date the 1st of january 3463 was actually 16.13.11.2.12, the only people who still use this calendar are new age cults.

Biblical calendar
The biblical calendar is one of the strangest calendars in use, it starts on the 25th of December in the year 4004 BCE, the supposed date God created the earth. The calendar is split up into 5 ages, The Age Of Creation (from the first to the seventh day of creation), The Age Of Adam (from the eighth day to the 25th of December 2348 BCE), The Age Of Noah (from 2348 BCE to the 25th of December 1338 BCE), The Age Of Mozes (from 1338 BCE to the 25th of december 1 CE) and The Age Of Christ (from 1 to current day). The main theory on when the fifth age will end and the sixth will begin is the supposed day of armageddon. Every age is also split into several eras. The first age is split into 2 eras: The Era Of Creation, which starts on the first and ends on the sixth day, The Era Of Rest, which starts and ends on the seventh day. The other ages are each split into 3 eras, these eras are called the “Nth era of the Nth age”. For example the second age is split into: The First Era of The Second Age, The Second Era of The Second Age and The Third Era of The Second Age. Another way they calculate time is with times, a time is 360 years long. We are currently in the 22nd time. Most creationist believe that the world will end somewhere during the 24th time (3917-4277) as supposedly Jesus was born in the 12th time and since Jesus is the center of everything, the world will end 12 times after Jesus was born. Confusingly the biblical calendar also has a so called century, which isn’t 100 years long but is in fact 27.453 days (around the 76-79 years) or the time between the appearance of Halley’s comet. A year on the calendar is still just as long as on the Gregorian calendar, only it starts on december 25th and ends on december 24th. The year is split into 12 months, each is 30 days long, these months were all named after an apostle, sometimes the suffix -month was removed. The months are: Peter-month, James-month, John-month, Andrew-month, Nathanael-month (sometimes also called Bartholomew-month), The Second James-month, Jude-month (sometimes also called Thaddeus-month), Matthew-month (also known as Levi-month), Philip-month, Simon-month, Thomas-month, Judas-month. This only adds up to 360, so inbetween the sixth and seventh month (Second James-month and Jude-month) an extra 5 days form what is called the Quinque Alter Dies (5 other days), shortened to Q.A.D. and latter shortened to what it is often called today Qwaid, during a leap year an extra day is added to the Q.A.D., turning it into the Sex Alter Dies or S.A.D, which became Saide. The biblical calendar never underwent the Parker Adjustment. The days of the week are called: The Day Of Light And Darkness (Monday), The Day Of Heaven (Tuesday), The Day Of The Seas, The Land And Plants (Wednesday), The Day Of The Sun, The Moon And The Stars (Thursday), The Day Of Creatures In The Water And The Sky (Friday), The Day Of Animals And People (Saturday), The Day Of Rest (Sunday).

Yet another way for them to write the date is the Numerare Diem Incipiens A Christus (or N.D.I.A.C., later Endiaic), this is simply writing counting the days starting from 25th of December 1. The first of January 3463 was Endiaic 1,264,114.

Julian date
The Julian date is not an actual calendar, but instead is used to count the days. The calendar begins on 12:00 on Monday, January first 4713 B.C. The notation is made up of a number that counts the days and a second number which is placed behind a point. This second number shows the time, for example .0 is 12:00, .25 is 18:00, .5 is 00:00 and .75 is 6:00. By this calendar 00:00 January first 3463 was actually Julian date: 2985894.5. A newer version of the Julian date was later implemented called the Einsteinian date, this version starts on 12:00 Monday, January first 1877 and works the same as the Julian date, according to this calendar Albert Einstein was born on 803.X, and 00:00 January first 3463 was 579275.5.