Dating and time systems

There are a multitude of dating systems in use throughout the galaxy. Measuring time has been standardised to an extent, but dating systems are still very diverse throughout the galaxy.
== Terran calendars ==
The Terran Federation and the Domions use various calendars. There are local calendars which are based on a single planet. These take into account many elements, such as is the planet a satellite of a gas giant, it's revolution and rotation speed etc. These are used on every planet other than Earth, but the Earth calendar is used alongside every other calendar. 
The Federation makes use of local and universal times. Most Commonwealths are located on planets with rotations lasting anywhere from 15 to 35 hours. Each Commonwealth has their own time system with a number of hours is closest to the Earth's hours for that rotation. For example, a world which has a rotation lasting 1943 standard minutes would have a time system with a number of hours equal to 32, as 32 sixty-minute long hours equal a total of 1920 standard minutes. However, the 23 minutes remaining do not exist in the time system, instead each time unit superior to a second for that planet is stretched out to compensate. For this planet specifically, each minute would instead be 60.72s long. Each Commonwealth will also use Earth's time. The universal time used throughout the Federation is that of London, Earth. This time is mostly used for stock market openings and other events which happen independently of local times. 
==== Old Earth calendar ====
The Old Earth calendar is the calendar based on the Old Earth Gregorian calendar. Each year has 365 days and 12 months, with leap years every 4th year based on Earth's revolution. The months are named: January, February, March, April, May, June, July, August, September, October, November and December. There are four seasons: winter, spring, summer and autumn (sometimes called fall). It is divided into two ages: Before Christ (BC) and Anno Domini (AD). The separating date is in the year 1BC, supposedly when the Old Earth Christian prophet, Jesus of Nazareth, was traditionally born, in -2072 BU. Whilst the Terran government does not use this calendar officially, it is in widespread use today and is still one of the most popular calendars in the Federation. This wiki uses this calendar. 
==== Terran calendar ====
The Terran calendar is the official calendar of the Terran Federation. Each year has 365 and 12 months, with leap years every 4th year. However unlike the Old Earth calendar, there 7 thirty day months and 5 thirty-one day months every year, and 6 thirty and 6 thirty-one day months in leap years. Many people use the four seasons with this calendar, but due to its interplanetary use seasons are not officially part of the calendar. The month names remain the same. It is divided into two ages: Before the Unification (BU) and After the Unification (AU). The separating date is in the year 0, when the First Commonwealth was formed, in 2072 AD. The Terran government uses this and only this calendar officially. Local calendars may be used alongside it. It is in widespread use and is often used in conjunction with the Old Earth calendar. 
==== New Terran calendar ====
The New Terran calendar is a rarely used calendar of the Terran Federation. It uses the same month structure as the Terran calendar It is divided into three ages: Before the Old Ages (BOA), the Old Ages (OA) and the Terran Age (TA). BOA ends in 1BC, and OA ends in 2072AD. It is extremely rarely used. It was originally intended to replace the Terran calendar, but its use was nearly non existent. 
==== Dominion calendars ====
Each Dominion has their own calendar. Each Dominion receives two calendars, the "Dominian" calendar and the Autonomous calendar. The Dominian calendar has the same month structure as the Terran calendar. The year zero starts upon the integration of the nation as a Dominion. The Autonomous calendar has a month structure based on the homeworld of said Dominion. Its year zero also starts upon integration as a Dominion. Dominions officially use both these calendars, but often use them alongside one of their native calendars. These native calendars can be recognized as official by the Dominion if they so wish. 
== Alien calendars ==
=== Galactic Standard Calendar ===
The Galactic Standard Calendar is a calendar which was made by Surben and Mirdesh scholars. It is in widespread use in the Surben Republic, Mirdesh Federation and Ur-Han. It has 28 months with 18 days each. It is divided into two ages: Before the Common Age (BCA) and Common Age (CA). The year 0 marks the first contact of the Surben Republic and Mirdesh Federation in 1987AD or -85BU. 
=== Ur-Han Royal calendar ===
The Ur-Han Royal calendar is the official calendar of the Ur-Han. It has 5 months with 43 days each. It is divided into six ages: Ancient (ANC), Barbarian (BAR), Standard (STA), End Times (ET), Royal (ROY) and Stellar (STL). Ancient ends in -3963BC or -6035BU, Barbarian ends in -2832BC or -4904BU, Standard ends in 1235AD or -837BU, End Times ends in 1289AD or -783BU, Royal ends in 2003AD or -69BU and Stellar is ongoing. 
=== Menya calendar ===
The Menya calendar is the official calendar of the Menya Union. The Terran calendar is used alongside it. It has 14 months with 32 days. It has two ages: Old Menya (OM) and New Menya (NM). The year zero is in 2286 when the Menya Union was formed.
=== Tesrat calendar ===
The Tesrat calendar is a calendar created in the Terran Federation for the Tesrat Republic. It was built on the principle of Autonomous (dominion) calendar. It has 16 months, with 15 months having 30 days each and the last month has 32 days. The year zero is the year 2648AD or 576AU, known as Liberation year. The age preceding the Liberation is known as the Old Age (OA) and the one following it is known as Free Age (FA). The Tesrat Republic also uses the Galactic Standard calendar, and used to use the Ur-Han Royal calendar. 
=== Other calendars ===
There are over 43 other calendars in use. Most of these are calendars in widespread use by a single species, most often in the Surben Republic, Mirdesh Federation or the Dominions. There are also other minor calendars used by major species, such as the Ab urbe condita Terran calendar or the Human calendar, starting in 753BC and 10000BC respectively.