Touhou Calendar

Upcoming:
12/9: Hifuu Club Day
12/10: IchiFuto Day
12/12: Hifuu Hifuu Day
12/21: Letty Solstice
12/24: Yaku-ristmas Eve

12/4 is Hecatia Day, y'know? #12月4日はヘカーティアの日 (p|t)

December's birthstone is Lapis Lazuli. 0(Wa)4(yon)=wayon, a phrase Hecatia says in the LoLK extra stage, sometimes used as her fan "catchphrase"

Upcoming:
12/4: Hecatia Day
12/9: Hifuu Club Day
12/10: IchiFuto Day
12/12: Hifuu Hifuu Day
12/21: Letty Solstice

11/27 is Megumu Day! #11月27日は飯綱丸龍の日 (p|t) #11月27日は飯綱丸の日 (p|t)

Goroawase: 1(i)1(i)2(zu)7(na)=Iizuna(maru)

11/24 is Good Gardener Youmu Day! #11月24日は妖夢の日 (p|t) #11月24日はいい庭師の日 (p|t)

Goroawase: 11(ii)24(nishi)=Ii Niwashi (Good Gardener), like Youmu

Upcoming:
11/27: Megumu Day
12/4: Hecatia Day
12/9: Hifuu Club Day
12/10: IchiFuto Day
12/12: Hifuu Hifuu Day

11/19 is Good Iku-san Day! #11月19日はいい衣玖さんの日 (p|t)

Goroawase: 11(ii)1(i)9(ku) = Ii Iku, "Good Iku"

11/18 is Jo'on Day! #11月18日は女苑の日 (p|t) #11月18日は依神女苑の日 (p|t)

The Birth Flower on 11/18 is the Himejo-en (姫女苑), with the same characters as Jo'on's name

Upcoming:
11/18: Jo'on Day
11/19: Good Iku-san Day
11/24: Youmu Day
11/27: Megumu Day
12/4: Hecatia Day

11/14 is Eika Day! #11月14日は戎瓔花の日 (p|t)

11/14 was dubbed Good Stone Day (11(ii)14(ishi)=いい石) by Yamanashi Stone Industry Association in 1999. Eika likes to stack stones

11/12 is Good Hifuu Day! #いい秘封の日 (p|t) #11月12日はいい秘封の日 (p|t)

Goroawase: 11(ii, JP for "good") 12 (hifuu, as in hifuu club)

11/11 is Onbashira Day! #11月11日は御柱の日 (p|t)

11/11 looks like onbashira sticking up from the ground

11/11 is Satori Day! Truly magnificent, it defies comparison to any other. #11月11日はさとりの日 (p|t)

In SCoOW vol. 5's cross review, Satori rates herself at an 11/10. As such she is linked to the number 11

Well, well! 11/10 is Kisume Day! #11月10日はキスメの日 (p|t)

Goroawase: 1(i)1(i)10(do)=いい井戸 (Good Well)

Upcoming:
11/11: Satori Day, Onbashira Day
11/12: Good Hifuu Day
11/14: Eika Day
11/18: Jo'on Day
11/19: Good Iku-san Day
11/24: Youmu Day

11/09 is Good Okuu Day! #いいお空の日 (p|t)

Goroawase: 1(i)1(i)0(O)9(kyuu)=ii Okuu (Good Okuu)

11/06 is Good Reimu Day! #いい霊夢の日 (p|t)

Goroawase: 1(i)1(i)0(Rei)6(mu)=ii Reimu (Good Reimu)

11/05 is Good Renko Day! #いい蓮子の日 (p|t)

Goroawase: 1(i)1(i)0(Re)5(ko)=ii Renko (Good Renko)

Upcoming:
11/5: Good Renko Day
11/6: Good Reimu Day
11/9: Good Okuu Day
11/10: Kisume Day
11/11: Satori Day, Onbashira Day
11/12: Good Hifuu Day
11/14: Eika Day

10/28 is Double Koishi Day! #10月28日はこいしちゃんx2の日 (t)

Gorowase: 1028 = 2*514, and 5(Ko)1(i)4(shi)

Upcoming:
10/28: Double Koishi Day
11/5: Good Renko Day
11/6: Good Reimu Day
11/9: Good Okuu Day
11/10: Kisume Day

☢️CAUTION☢️ 10/26 is Nuclear Power Day and Okuu Day! #10月26日はお空の日 (p|t)

10/26 is Atomic Power Day in Japan

10/25 is Tojiko Day! #10月25日は屠自古の日 (p|t)

Goroawase: 10(To)2(ji)5(ko)

Upcoming:
10/25: Tojiko Day
10/26: Okuu Day
10/28: Double Koishi Day
11/5: Good Renko Day
11/6: Good Reimu Day

10/16 is ReiMariAli Day! #10月16日はレイアリマリの日 (p|t)

Goroawase: 10 1(i)6(ro)=10 Colored. The idea is that Alice's seven colors, Reimu's red and white, and Marisa's black and white sum to ten colors (if you consider white is common between them, sort of)

10/15 is Mushroom Day and Doll Day, so it's MariAli Day! #10月15日は魔理沙とアリスの日 (p|t) #10月15日はマリアリの日 (p|t)

Marisa is associated with mushrooms, and Alice is associated with dolls

Upcoming:
10/15: MariAli Day
10/16: ReiMariAli Day
10/25: Tojiko Day
10/26: Okuu Day
10/28: Double Koishi Day

10/12 is Ushi-Matsuri and Okina Day! #10月12日は隠岐奈の日 (p|t)

Ushi-Matsuri (牛祭) is a festival held at Kōryū-ji Temple on 10/12, in which a priest wearing a Matarajin mask rides an ox

10/10 is Ten Desires Day! #10月10日は東方神霊廟の日 (p|t)

10/10, like Ten Desires

Nya! 10/10 is Chen Day! #10月10日は橙の日 (p|t)

Ten sounds like Chen!