A saijiki (歳時記, lit. "year-time chronicle") is a list of Japanese kigo (seasonal terms) used in haiku and related forms of poetry. An entry in a saijiki usually includes a description of the kigo itself, as well as a list of similar or related words, and some examples of haiku that include that kigo.^[1] A kiyose (季寄せ) is similar, but does not contain sample poems. Modern saijiki and kiyose are divided into the four seasons and New Year, with some containing a further section for seasonless (無季, muki) topics. Each seasonal section is further divided into a standard set of categories, each containing a list of relevant kigo. The most common categories are the season, the heavens, the earth, humanity, observances, animals and plants.

Japanese seasons

In the Japanese calendar, seasons traditionally followed the lunisolar calendar with the solstices and equinoxes at the middle of a season. The traditional Japanese seasons are:

• Spring: 4 February–5 May
• Summer: 6 May–7 August
• Autumn: 8 August–6 November
• Winter: 7 November–3 February

In categorising kigo, a saijiki or kiyose divides each season into early, middle, and late periods, as follows:^[2]

• Early spring: 4 February–5 March
• Mid-spring: 6 March–4 April
• Late spring: 5 April–5 May
• Early summer: 6 May–5 June
• Mid-summer: 6 June–6 July
• Late summer: 7 July–7 August
• Early autumn: 8 August–7 September
• Mid-autumn: 8 September–7 October
• Late autumn: 8 October–6 November
• Early winter: 7 November–6 December
• Mid-winter: 7 December–4 January
• Late winter: 5 January–3 February