The chronological sequence of the events in Kaguya-sama wa Kokurasetai.

Time Period Timeframe/Date Events & Arcs Specific Sources Notes
First Year: 1st Term Kaguya and Miyuki enroll into Shuchiin Academy

1 week period
April Kaguya and Shirogane's first meeting

Chapter 121

July End of July Miyuki gets nominated in the General Student Assembly Volume 4 Extra
Summer Break
First Year: 2nd Term
September   Miyuki becomes President,

Kaguya becomes Vice President

Volume 4 Extra
October Two months Kuuguya Period Volume 4 Extra
November Rumours about Kaguya and Miyuki going out are spreading

1st half of Chapter 1

Volume 4 Extra
January 2016 Calendar in Chapter 18 Weekdays inconsistent with the actual calendar system. See 9/9 & 1/1 in Chapter 51 and 11/6 in Chapter 100
February 14th Chapter 59
Second Year: 1st Term Miko Iino and Yu Ishigami enroll into Shuchiin Academy
Shirogane meets Ishigami
Chapter 89
April Ishigami joins Student Council Volume 4 Extra
2nd Half of Chapter 1
May Middle of May Nagisa Kashiwagi gets confessed to by someone Chapter 6 Chapter 48
Shirogane and Kaguya's Anniversary

Chapter 8

June - Chapter 18
25th-26th Heartpounding Shopping Trip

Chapter 19

27th French Exchange Party

Chapter 20

28th Uniform Change

Chapter 21

July End of Final Exams

Chapter 31

Chapter 33
Heartpounding Sick Visit
Chapter 34-35
Summer Break 31st End of 1st Term

Chapter 40

August Half a month
14th Chapter 41 Calendar
15th Chapter 42 Chapter 44 Twitter
20th Fireworks Arc

Chapter 44-45

Chapter 40
Second Year: 2nd Term First day Chapter 46
September 5th Birthday PlanningChapter 51
7th Shopping TripChapter 52
9th Shirogane's 17th Birthday

Chapter 53

10th Chapter 54
Moon Viewing

Chapter 56

Chapter 57
Chapter 58
67th Student Council is disbanded

Chapter 59-60

Two days
Chapter 61
October Art Class Elective begins

Chapter 62

According to Chapter 47 Second Term Electives Start in October
End of summer

and day after

Uniform Change

Chapter 63

Chapter 64
15th Election Arc, 68th Student Coucil is formed
Chapter 67-68
Flyer at the start of Chapter 61
Athletic Festival

Chapter 86-90

Chapter 91
Karaoke Mixer

Chapter 93-94

15 days before Rap Arc Flashback in Chapter 107
November Six Month Anniversary

Chapter 97

Maki Shijo

meets the student council

Chapter 98

Some time after Nov 06 Phone Arc

Chapter 100-102

Midterm Exams

Chapter 105

Rap Battle

Chapter 108

December 20th Culture Festival day 1

Chapter 122-127

21st Culture Festival day 2
January 1st School Trip,

Kaguya's Birthday