Timekeeping

As is natural for a universe governed by physics, the precise orbital and rotational period of every planet is different. In the first decades, interstellar colonies were separated by years of travel time. Humans in Kyandor, Sol, New Sol, and Rangel were unable to communicate with one another due to communications delays lasting centuries, and travel times lasting between 20 and 50 years. In essence, each world was a totally isolated pocket of civilization until the Interstellar Relay Gate was invented in the 3150s. 
When contact was made between long-separated groups, exactly how transit should be scheduled was up for debate. Many systems were proposed and most, if not all of them, are still in use in some areas of the galaxy. 
== Gregorian Calendar ==
The Gregorian Calendar was the dominant calendar on Earth for centuries before being abandoned in favor of the Solar Standard Calendar. Its measurements are based upon the orbital and rotational periods of Earth and its moon. 
Name 	Earth Days	Based Upon
Year 	365.256 	Orbital Period of Sol III / Earth
Month 	~ 30 	Approximate Orbit of Sol IIIa / Luna
Week 	7 	1/4 of One Lunar Orbit
Day 	1 	One Solar Day of Sol III / Earth
Hour 	 	1/24th of One Day
Minute	 	1/60th of One Hour
Second	 	1/60th of One Minute
=== Epoch ===
The gregorian calendar starts with when Jesus of Nazareth is believed to have been born. These years are followed by either "AD" or "BC", meaning Anno Domini (Latin: The Year of Our Lord) and Before Christ. The secular name for these eras are "CE" and "BCE", meaning Common Era and Before Common Era.
== Darian Calendar ==
The standard calendar of Mars and her colonies until 2350 and after 2393. It is based upon Mars' orbital and rotational movements. In each group of six months out of the total of 24, the first five have 28 days, while the last has 27. The only exception is that the last month, Vrischika, has one additional day on martian leap years. 
Name 	Local Days	Earth Days 	Based Upon
Year 	668.591 	686.86 	Orbital Period of Sol IV / Mars
Month 	27 or 28 	27.742 or 28.767	1/24th of One Year
Week 	6 or 7 	6.165 or 7.192 	1/4th of One Month
Day 	1 	1.027 	One Solar Day of Sol IV / Mars
Hour 	 	 	1/24th of One Day
Minute	 	 	1/60th of One Hour
Second	 	 	1/60th of One Minute
=== Martian Months ===
Mars' months are named for the signs of the zodiac, alternating between their names in Latin and in Sanskrit. For instance, Libra, the 21st month, is followed by Tula, the 22nd month. Both words refer to the same sign, but in different languages. Due to its orbital eccentricity, the seasons are not uniform in length.
Northern Season	Months 	 	 	 	 	 	
Winter 	Virgo (Partial) 	Kanya 	Libra 	Tula 	Scorpius	Vrischika 	
Spring 	Sagittarius 	Dhanus	Capricornus	Makara	Aquarius	Kumbha 	Pisces
Summer 	Mina 	Aries 	Mesha 	Taurus	Rishabha	Gemini 	Mithuna (Partial)
Autumn 	Mithuna (Partial)	Cancer	Karka 	Leo 	Simha 	Virgo (Partial)	
=== Epoch ===
The Darian Calendar began in 1609 CE / 11609 HE. In that year, Johannes Kepler made use of Tycho Brahe's observations of Mars to discover the laws of planetary motion, and Galileo Galilei made his first observations of the planet via telescope. This is referred to as the Telescopic Epoch. When Mars was colonized in 2083 CE, the martian year was AT 265, mere weeks from the year 266. The calendar was changed in 416, and was changed back in 439 when Mars regained independence from the Solar Union. 
== Solar Standard Calendar ==
The Solar Standard Calendar was adopted in 2350 CE. It features seven months with 30 days (January, February, April, May, July, August, and November), and five with 31 (March, June, September, October, and December). It follows the same leap year rules as the Gregorian calendar, with one leap year every four years unless the year can be evenly divided by 100, with exceptions to that rule made for years divisible by 400. Leap days are still placed at the end of February for traditional reasons. 
Name 	Earth Days	Based Upon
Year 	365.256 	Orbital Period of Sol III / Earth
Month 	30 or 31 	Approximate Orbit of Sol IIIa / Luna
Week 	7 	1/4 of One Lunar Orbit
Day 	1 	One Solar Day of Sol III / Earth
Hour 	 	1/24th of One Day
Minute	 	1/60th of One Hour
Second	 	1/60th of One Minute
=== Epoch ===
The Solar Standard Calendar either uses the Holocene Epoch, measuring years since the approximate birth of agriculture, or the old standard Common Epoch, which was based upon the approximate birth year of Jesus Christ of the Christian faith. The difference between the two is roughly 10000 years, making the date of its adoption either 2350 CE or 12350 HE. 
== Kyandor Short Calendar ==
The Kyandor Short Calendar was created in an attempt to roughly approximate an Earth year using Kyandor's extremely short orbital period.
Name 	Local Days	Earth Days	Based Upon
Long Year	263.697 	362.584 	8 Revant Years
Year 	32.962 	45.323 	Orbital Period of Kyandor B / Revant
Day 	1 	1.375 	One Solar Day of Kyandor B / Revant
=== Epoch ===
The Kyandor Short calendar's epoch is based upon when the liveship Traveler arrived in the Kyandor system, in the year 2925 CE/12925 HE.