coffeebeforescience | Annotated Timeline

2490s

March 19, 2492: Catherine Elizabeth Halsey is born in Port Vernon, Endymion

2510s

August 8, 2510: Beginning of Halsey's journal
July 21, 2517: Aboard the Han with Jacob Keyes
August 17, 2517: Halsey and Keyes meet John
September 16, 2517: Halsey and Keyes part ways
September 23, 2517: Indoctrination and training of the SPARTAN-IIs begins

c. July 12, 2519: John promoted to Squad Leader

2520-2524

October 15, 2521: Third gen AIs enter service
June 5, 2522: Accepts chief scientist position with ONI

November 17, 2524: Meets with Lieutenant Keyes at University of Calippus (date possibly incorrect based on Miranda's DOB)

2525

February 11: First contact at Harvest
February 28: Miranda Halsey is born

March 9: Augmentation procedures begin
March 30: Survivors of augmentation process mustered for funeral service

April 22: John fights and kills ODSTs in gym

September 14: First Spartan mission

November 2: Spartans complete training; awarded rank of Petty Officer Second Class
November 27: Spartans given MJOLNIR; death of Samuel-034, first Spartan to die in combat

2530s

May 25, 2537: Halsey and AI Kalmiya make breakthrough in deciphering meta-Covenant language (Forerunner)

2540s

March 18, 2543: Halsey recovers her journal

Unknown date, 2544: Halsey kidnapped by Covenant forces

September 5, 2547: Possible date of glassing of Endymion (Halsey reflects on KIA lists)

May 21, 2549: Halsey clones her brain for the purposes of creating an advanced 3rd gen AI
July 29, 2549: Removal of clone brains and incineration of the clones
September 9, 2549: Halsey watches the glassing of Arcadia
November 7, 2549: Cortana's "birthday"

2550s

April 6, 2550: Miranda Keyes promoted to Commander

February 20, 2551: UNSC Hopeful taken out of Reach orbit – site of SPARTAN-III augmentations

2552 (pre-Reach)

July 24: Halsey discovers/is informed of existence of NOBLE Team

August 2552

August 12: Halsey meets with Jacob Keyes and John-117 on Reach
August 27: Reunited with the remaining Spartans (John, Kelly, Fred, Linda, Isaac, William, Li)
August 29: John-117 outfitted with Cortana; surgical implant

August 30:
Reach attacked by full Covenant force
Dr. Catherine Halsey rescued by members of Spartan Red Team (First Strike: p. 147)

2552 (post-Reach)

September 7: Halsey and Spartans are found by Covenant forces
September 12 – after Slipspace bubble: John-117 offered medical details of Sgt. Avery Johnson by Dr. Halsey regarding the Flood; Halsey discovers that Spartans are marked "MIA" instead of KIA; formulates plan to save remaining Spartans
September 23: Cryotube containing Linda-058 recovered; signal received by captured covenant vessel (John, Cortana, et al) "Oly Oly Oxen Free"; Kelly protects Halsey from Covenant attack

c. November 3: News of Halo incident/Jacob's death obtained from Cortana's mission log; Kelly awakens; Halsey theorizes arms race for Forerunner tech between humans and Covenant; discovered by SPARTAN-III group led by Kurt