Old Duisien Calendar

The Old Duisien Calendar was a timekeeping system used in ancient Duisien and currently in Northudankton as the Modern Northu Calendar. It consisted of twelve months, each with a distinct set of days. The calendar followed a pattern where the 1st, 11th, 21st, and last days of each month held particular significance. The months in the Old Duisien Calendar were named Primarius, Secundarius, Tertius, Quartarius, Quintarius, Sextarius, Septimarius, Octavarius, Nonarius, Decarius, Unecarius, and Ulticarius. Each month had its own series of designated days, starting with Primus, which marked the first day of the month.

The Modern Northu Calendar was derived from the Old Duisien Calendar and is currently used in Northudankton. It retains the same twelve-month structure with modified names. The months in the Modern Northu Calendar are named Primarius, Secundarius, Tertius, Quartarius, Quintarius, Sextus, Septimus, Octavus, Nonus, Decarius, Unecarius, and Ultimarius.

The Old Duisien Calendar's system of designated days has also been incorporated into the Modern Northu Calendar. These days are collectively referred to as Principus and hold a significant place within the calendar. Principus includes four main days: Primus, Decimus, Vicesimus, and Ultimus, which mark crucial milestones and transitions throughout each month. They shape the rhythm of time and add a sense of order and purpose to the calendar.

In addition to the significant days, the Old Duisien Calendar also had intermediate days called Interdimus. These days occur between the main four days and contribute to the overall progression and anticipation within the month. They build up towards the Principus days, creating a sense of suspense and further enhancing the structure of the calendar.

On May 21, Vicesimus Quintarius, 2023, Northudankton officially adopted the Days of the Old Duisien Calendar into their own timekeeping system. This adoption allows the modern society to connect with the ancient Duisien civilization and its unique timekeeping practices. The Old Duisien Calendar, with its distinct months, designated days, and the concept of Principus and Interdimus, offers insights into the historical and cultural aspects of timekeeping in Northudankton.

## Months:

### Ancient Duisien:

1. Primarius (January)
2. Secundarius (February)
3. Tertius (March)
4. Quartarius (April)
5. Quintarius (May)
6. Sextarius (June)
7. Septimarius (July)
8. Octavarius (August)
9. Nonarius (September)
10. Decarius (October)
11. Unecarius (November)
12. Ulticarius (December)

### Modern Northu:

1. Primarius (January)
2. Secundarius (February)
3. Tertius (March)
4. Quartarius (April)
5. Quintarius (May)
6. Sextus (June)
7. Septimus (July)
8. Octavus (August)
9. Nonus (September)
10. Decarius (October)
11. Unecarius (November)
12. Ultimarius (December)

## Days:

* **Primus *(1st day of the month) [KALENDS]***
	+ Decimus in 9d *(2nd day of the month)*
	+ Decimus in 8d *(3rd day of the month)*
	+ Decimus in 7d *(4th day of the month)*
	+ Decimus in 6d *(5th day of the month)*
	+ Decimus in 5d *(6th day of the month)*
	+ Decimus in 4d *(7th day of the month) [Nones]*
	+ Decimus in 3d *(8th day of the month)*
	+ Decimus in 2d *(9th day of the month)*
	+ Decimus in 1d *(10th day of the month)*
* **Decimus *(11th day of the month)***
	+ Vicesimus in 9d *(12th day of the month)*
	+ Vicesimus in 8d *(13th day of the month)*
	+ Vicesimus in 7d *(14th day of the month)*
	+ Vicesimus in 6d *(15th day of the month) [Ides]*
	+ Vicesimus in 5d *(16th day of the month)*
	+ Vicesimus in 4d *(17th day of the month)*
	+ Vicesimus in 3d *(18th day of the month)*
	+ Vicesimus in 2d *(19th day of the month)*
	+ Vicesimus in 1d *(20th day of the month)*
* **Vicesimus *(21st day of the month) [THIS EXAMPLE HAS 31 DAYS]***
	+ Ultimus in 9d (22nd day of the month)
	+ Ultimus in 8d (23rd day of the month)
	+ Ultimus in 7d (24th day of the month)
	+ Ultimus in 6d (25th day of the month)
	+ Ultimus in 5d (26th day of the month)
	+ Ultimus in 4d (27th day of the month)
	+ Ultimus in 3d (28th day of the month)
	+ Ultimus in 2d (29th day of the month)
	+ Ultimus in 1d *(30th day of the month)*
* **Vicesimus (21st day of the month) *[THIS EXAMPLE HAS 30 DAYS]***
	+ Ultimus in 8d (22nd day of the month)
	+ Ultimus in 7d (23rd day of the month)
	+ Ultimus in 6d (24th day of the month)
	+ Ultimus in 5d (25th day of the month)
	+ Ultimus in 4d (26th day of the month)
	+ Ultimus in 3d (27th day of the month)
	+ Ultimus in 2d (28th day of the month)
	+ Ultimus in 1d (29th day of the month)
* **Vicesimus (21st day of the month) *[THIS EXAMPLE HAS 29 DAYS]***
	+ Ultimus in 7d (22nd day of the month)
	+ Ultimus in 6d (23rd day of the month)
	+ Ultimus in 5d (24th day of the month)
	+ Ultimus in 4d (25th day of the month)
	+ Ultimus in 3d (26th day of the month)
	+ Ultimus in 2d (27th day of the month)
	+ Ultimus in 1d (28th day of the month)
* **Vicesimus (21st day of the month) *[THIS EXAMPLE HAS 28 DAYS]***
	+ Ultimus in 6d (22nd day of the month)
	+ Ultimus in 5d (23rd day of the month)
	+ Ultimus in 4d (24th day of the month)
	+ Ultimus in 3d (25th day of the month)
	+ Ultimus in 2d (26th day of the month)
	+ Ultimus in 1d (27th day of the month)
* **Ultimus *(Last day of the month)***

## Names of Every Main Day

1. Here's a list of all the special Duisien (Northu) days of the year, along with their corresponding dates in the Gregorian calendar:
	1. Primarius Primus - January 1st
	2. Primarius Decimus - January 11th
	3. Primarius Vicesimus - January 21st
	4. Primarius Ultimus - January 31st
	5. Secundarius Primus - February 1st
	6. Secundarius Decimus - February 11th
	7. Secundarius Vicesimus - February 21st
	8. Secundarius Ultimus - February 28th (or 29th during leap years)
	9. Tertius Primus - March 1st
	10. Tertius Decimus - March 11th
	11. Tertius Vicesimus - March 21st
	12. Tertius Ultimus - March 31st
	13. Quartarius Primus - April 1st
	14. Quartarius Decimus - April 11th
	15. Quartarius Vicesimus - April 21st
	16. Quartarius Ultimus - April 30th
	17. Quintarius Primus - May 1st
	18. Quintarius Decimus - May 11th
	19. Quintarius Vicesimus - May 21st
	20. Quintarius Ultimus - May 31st
	21. Sextus Primus - June 1st
	22. Sextus Decimus - June 11th
	23. Sextus Vicesimus - June 21st
	24. Sextus Ultimus - June 30th
	25. Septimus Primus - July 1st
	26. Septimus Decimus - July 11th
	27. Septimus Vicesimus - July 21st
	28. Septimus Ultimus - July 31st
	29. Octavus Primus - August 1st
	30. Octavus Decimus - August 11th
	31. Octavus Vicesimus - August 21st
	32. Octavus Ultimus - August 31st
	33. Nonus Primus - September 1st
	34. Nonus Decimus - September 11th
	35. Nonus Vicesimus - September 21st
	36. Nonus Ultimus - September 30th
	37. Decarius Primus - October 1st
	38. Decarius Decimus - October 11th
	39. Decarius Vicesimus - October 21st
	40. Decarius Ultimus - October 31st
	41. Unecarius Primus - November 1st
	42. Unecarius Decimus - November 11th
	43. Unecarius Vicesimus - November 21st
	44. Unecarius Ultimus - November 30th
	45. Ultimarius Primus - December 1st
	46. Ultimarius Decimus - December 11th
	47. Ultimarius Vicesimus - December 21st
	48. Ultimarius Ultimus - December 31st