二日

/putuka/ → /fut͡suka/

From Old Japanese. First attested in the Nihon Shoki of 720.^[1]

Analyzable as a compound of 二 (futsu, “two”, irregular reading, apparently a shift from expected reading futa) +‎ 日 (ka, “day”, uncommon variant only occurring in certain compounds of ancient derivation).

• (Tokyo) ふつか (Heiban – )^[2]
• IPA^(key):

二(ふつ)日(か) • (futsuka) 

1. two days, a two-day period
2. the second day after some set point in time
3. the second day of the month
4. (historical) during the Edo period, the two-day period of the day of 大祭 (taisai, “major festivals”) and the preceding day's 宵祭り (yoi matsuri, “eve-festivals”)
5. short for 二日灸 (futsuka-kyū), moxibustion traditionally performed on the second of February or August in the belief that this conferred year-long good health

• 二日酔(ふつかよ)い (futsuka yoi, “a hangover”, literally “two-day intoxication”)
• 二日(ふつか)心(ごころ) (futsukagokoro)
• 二日(ふつか)灸(きゅう) (futsukakyū)
• 二日(ふつか)月(づき) (futsukazuki)
• 二日(ふつか)払(ばら)い (futsuka barai)

Compound of 二 (futa, “two”, used in counting) +‎ 日 (hi, “day”). Generally only found in instances of counting, as in ひとひふたひ (hitohi futahi, “one day, two days...”).^[1]

First cited in 1746.^[1]

• IPA^(key):

二(ふた)日(ひ) • (futahi) 

1. (archaic, possibly obsolete) two days, a two-day period