Hey all
Wondered if you guys had some thoughts on this. I thought I’d do an account of the 2540s and 2550s from a Covenant POV, fitting together canon events and other stuff going on elsewhere in the Empire that we’ve not seen in the books or games. I don’t want to outright go against canon while doing this, so I wondered if canon-nerds here could help me out! 
For now, here is the rough chronological framework I have come up with.
FIRST GRAND CYCLE OF LOYALTY, NINTH AGE OF RECLAMATION
(Tuesday February 20th 2525- Tuesday January 14th 2527)
SECOND GRAND CYCLE OF LOYALTY, NINTH AGE OF RECLAMATION
(Tuesday March 20th 2542- Tuesday February 11th 2544)
SECOND GRAND CYCLE OF TRUST, NINTH AGE OF RECLAMATION
(Tuesday February 11th 2544- Tuesday 4th January 2546)
SECOND GRAND CYCLE OF TOLERANCE, NINTH AGE OF RECLAMATION
(Tuesday 4th January 2546- Tuesday 28th November 2547)
SECOND GRAND CYCLE OF FELLOWSHIP, NINTH AGE OF RECLAMATION
(Tuesday 28th November 2547- Tuesday 21st October 2549)
SECOND GRAND CYCLE OF RECIPROCITY, NINTH AGE OF RECLAMATION
(Tuesday 21st October 2549-Tuesday 14th September 2551)
SECOND GRAND CYCLE OF ACCEPTANCE, NINTH AGE OF RECLAMATION
(Tuesday 14th September 2551- Tuesday 7th August 2553)
FIRST GRAND CYCLE OF LOYALTY, SECOND AGE OF ABANDONMENT
(Tuesday 7th August 2553- Tuesday 1st July 2555)
FIRST GRAND CYCLE OF TRUST, SECOND AGE OF ABANDONMENT
(Tuesday 1st July- Tuesday 24th May 2557)
FIRST GRAND CYCLE OF TOLERANCE, SECOND AGE OF ABANDONMENT
(Tuesday 24th May 2557-Tuesday 17th April 2559)
A “Grand Cycle” is the Covenant term for a year, comprising sixty three “Cycles”, or High Charity days (though to the human mind, a “Cycle” is better understood as a length of time equivalent to a week, made up as it is of 265 roughly hour-length units). One day on High Charity is equivalent to 11 days on Earth: therefore, one Covenant year is slightly shorter than two Earth years, at 693 Earth days.
I chose 63 as it is seven (obviously!) times nine, a number that seems to have special meaning for the Covenant. There are nine named Grand Cycles, at which point the count begins again. These are named for the positive traits the Covenant is held to exist on: Loyalty, Trust, Tolerance, Fellowship, Reciprocity, Acceptance, Respect, Understanding and Obedience.
The history will be a Grand Cycle by Grand Cycle chronicle written by an Unggoy deacon named Michik, and will be in the style of historical Byzantine world-chronicles, complete with extreme religious bias and violent language towards those Michik disapproves of.
Feedback, please! The aim is for me to be creative within canon, so unless something I write is outright contradicted by canon, please bear that in mind!
Thank y’all very much