Assassination Classroom Timeline
This took me a year. I combed through the entire manga. If you don’t appreciate it, I’m going to riot.
April 23- Nagisa goes to get sushi. this is something that Koro-sensei grades after the Sugino incident, so we know that happens after (chapter 2)
May 1- Irina Jelavić first arrives in Class 3-E (chapter 8)
May 28- Ritsu first arrives in Class 3-E. This isn’t directly stated, but she says her next evolution phase is “5-28-02;” if it’s her second attack on May 28th, that makes sense, and they previously said it was nearing the end of May. (chapter 20)
Early June- Maehara’s girlfriend cheats on him (chapter 23)
June 15- Itona first arrives in Class 3-E (chapter 29)
July 1- Sugaya brings henna to school. (chapter 37)
I made a mistake here and missed the date for Sugaya’s spotlight; because of it, the date for the bet is a continuity error.
BEFORE EDIT: July 2- Class E and Class A make the bet. the English on the shonen jump app says June 2, but I found the raw manga online and it says 7/2, which makes much more sense. I don’t know why the translators thought June was the seventh month. (chapter 51)
August- Lovro arrives for summer training. (chapter 57)
August 31- Last day of summer break. (chapter 72)
September- Beginning of the second semester. I think it can be assumed the assembly is on the first. (chapter 73)
September- Kayano makes a giant pudding during a three day weekend. Based on Japanese public holidays, this is likely Respect for the Aged Day (third Monday) or the Autumnal Equinox (22-23). (chapter 74)
September 28- A mysterious yellow lingerie thief strikes again. The English says it was the 28th at 3am, but the Japanese is too grainy to read. (chapter 83)
October 14- Class E receives their new P.E. uniforms. Four days since Irina’s birthday. (chapter 98)
October 18- Kidnapping. Three days have passed since Irina left. (chapter 101)
November- Career counseling. (chapter 112)
Mid-November- School festival. (chapter 115)
December- Finals. (chapter 121)
December 23-25- Kayano and Koro fight. She’s in the hospital for two weeks after. (chapter 142)
January 6- Nagisa &co visit Kayano in the hospital. She’s discharged two days later. (chapter 141)
January 18- Nagisa & Karma launch into space. (chapter 150)
February 3- Korosensei roleplays Christmas. “38 days left.” (chapter 154)
February 13- Everybody yells at each other about entrance exams. “28 days left.” (chapter 156)
February 13- Okano and Maehara go to karaoke after school. (chapter 158)
February 14- Valentine’s Day. (chapter 158-160)
March 6- Korosensei is trapped. Seven days left. (chapter 164)
March 13- Kunugigaoka graduation ceremony. (chapter 178) (date is also given in chapter 141)
