Tyerin is an alternate calendar. It is a geosolar calendar, which means it depends on the earth rotation and it's revolution around the sun.

It starts to midnight of December 21st, the first day of Northern winter.

## Time system

Time Conversion
Tyerian Unit Tyerain Conversion Gregorian Conversion Significance
Jubilee 50 Years 49.8984478101 Years Based off of the Hebrew "Year of Jubilee"
Year 4 (5) Seasons 364.258669014 Days 1 Revolution of the Earth
Season 3 Months 90.66919917 Days
Month 6 Weeks 30.223066391 Days
Week 5 Days 4.9863425925 Days
Day 10 Myriaseconds 0.9972685185 Days 1 Rotation of the Earth
Myriasecond 10 Kiloseconds 2.39344444442 Hours
Kilosecond 10 Hectoseconds 14.3606666665 Minutes
Hectosecond 100 Seconds 1.43606666665 Minutes
Second 1000 Miliseconds 14.3606666665 MIliseconds Uses metric prefixes
Milisecond 10 Myroseconds 14.3606666665 Microseconds
Myrosecond 100 Microseconds 1.43606666665 Microseconds

### Leap year

Leap years
Year Mid-Year Days Last Days First Days
4 5 0 0
32 5 1 0
620 5 1 1
6520 5 2 1

## Dating System

The dating system of the Tyerian Calendar is Day/Month/Year/Jubilee. Despite not being a month, The Mid-Year Week, also called Mercidoni, is the "7th month" in the dating system.

### Conversion Equation

Note: In the following equations "d" stands for the day of the year
To convert from the Tyerian Calendar to the Gregorian Calendar, use this equation:

To convert from the Gregorian Calendar to the Tyerian Calendar, use this equation:

### Epoch

The epoch of the Tyerian Calendar is the equivalent of the gregorian year: 1300 AD. Anytime before 1300, instead of listing a particular jubilee just has "BJ".

## Division of a Year

Seasons
Name Division Days
Winter 3 Months 90
Spring 3 Months 90
Mid-Year Week [nb 1] 1 Week 4 (5)
Summer [nb 1] 3 Months 94 (95)
Autumn 3 Months 90
1. Summer is longer than winter, due to the eliptical orbit of the Earth. It includes the Mid-Year Week, even though the Mid-Year Week is sometimes considered to not belong to a season.
Months
Name Number Season Gregorian Equivalent Gregorian Equivalent in a Standard Leap Year
Decari 1 Winter December 21–January 20 December 21–January 20
Ianari 2 Winter January 21–February 19 January 21–February 19
Febrari 3 Winter February 20–March 21 February 20–March 20
Martari 4 Spring March 22–April 20 March 21–April 19
Aprilari 5 Spring April 21–May 20 April 20–May 19
Mai'ari 6 Spring May 21–June 19 May 20–June 18
Mid-Year
(Mercidoni)
7 Summer June 20–June 22 June 19–June 22
Iunari 8 Summer June 23–July 22 June 23–July 22
Iulari 9 Summer July 23–August 21 July 23–August 21
Augustari 10 Summer August 22–September 20 August 22–September 20
Septari 11 Autumn September 21–October 20 September 21–October 20
Octari 12 Autumn October 21–November 19 October 21–November 19
Novari 13 Autumn November 20–December 20 November 20–December 20
Days of the Week
Name Number Type
Monday 1 Weekday
Tuesday 2 Weekday
Wednesday 3 Weekday
Thursday 4 Weekday
Friday 5 Weekend

## Holidays

US Holidays
Holiday Date
Tyerian New Years Decari 1
Christmas Decari 4
Kwanza Decari 5–Decari 11
New Years Eve Decari 10
New Years Decari 11
Epiphany Decari 16
MLK Jr. Day Decari 29
Ground Hog Day Ianari 13
Valentine’s Day Ianari 25
Jubilee Febrari 3
Good Day Febrari 13
St. Patrick’s Day Febrari 14
Easter Febrari 15
Cinco de Mayo Martari 25
Pentacost Aprilari 4
Father’s Day Mai'ari 1
Columbus Day Septari 21
Halloween Octari 10
All Saints’ Day Octari 11
Thanksgiving Novari 6
Chanukah Novari 17–Novari 24
Tyerian New Year's Eve Novari 30