Timeline

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

Time Period	Timeframe/Date	Events & Arcs	Specific Sources	Notes
First Year: 1st Term		Kaguya and Shirogane enroll into Shuchiin Academy
	1 week period
April		Kaguya and Shirogane's first meeting Chapter 121
May
June
July	End of July	Shirogane gets nominated in the General Student Assembly	Volume 4 Extra
		Shirogane has a fight with the 3rd years on the 'Student Council	Volume 4 Extra Chapter 8
Summer Break
First Year: 2nd Term
September		Shirogane 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
December
First Year: 3rd Term
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	Cubari Facaccimo creation		Chapter 59
March
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
	31st	Movie date Chapter 3	Date on the ticket after Shirogane buys it
June	-	Chapter 18
	25th-26th	Heartpounding Shopping Trip Chapter 19	Chapter 41, date of Shirogane's first message to Kaguya
	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	Calendar
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 Planning Chapter 51
	7th	Shopping Trip Chapter 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 67-69	Flyer at the start of Chapter 61
		Athletic Festival Chapter 86-90
		Chapter 91
		Karaoke Mixer Chapter 93-94
	15 days before Rap Battle	Flashback in Chapter 107
November		Six Month Anniversary Chapter 97
		Maki Shijo meets the student council Chapter 98
	Some time after Nov 06	Cell Phone Arc Chapter 100-102
		Midterm Exams Chapter 105
		Rap Battle Chapter 108
December	20th	Culture Festival day 1 Chapter 122-128
	21st	Culture Festival day 2 Chapter 129-138
	22nd	Chapter 139-142
	23rd	Chapter 143-148
Christmas Eve	24th (& 25th since some chapters take place after midnight)	Fujiwara's Christmas party Chapter 149-151 Tsubame's Christmas party (Ishigami's winter break story) Chapter 153-156 Maki's India Vacation Chapter 161
	26th	Second semester closing ceremony	Volume 12 Extra
		(Iino's winter break story) Chapter 158		Iino realises she can use Ishigami in this flashback
	27th	(Kaguya and Shirogane's winter break story) Chapter 159-160		Kaguya hasn't seen Shirogane since new years in Chapter 152
January	1st	Kaguya's Birthday
Second year: 3rd Term	7th	Third semester opening ceremony Chapter 152	Volume 12 Extra
February	1st	School Trip day 1 Chapter 179-182	Volume 12 Extra
	2nd	School Trip day 2 Chapter 182-186
	3rd	School Trip day 3 Chapter 187
	4th	School Trip day 4 Chapter 187
	14th	Valentine's Day Chapter 195
March
	1st and/or 2nd	Final Exams, Final Exam Results Chapter 198-199	Kaguya and Osaragi conversation in Chapter 189 (was changed in the volume version)
	3rd	Ishigami and Fujiwara's birthday Chapter 200
	10th	Third years graduate ceremony Chapter 202-204
	22nd	Third semester closing ceremony