一日
いちにち · ichinichi · JLPT N5 · noun
day
📅 一日 = one (ichi) + day (nichi): one whole day
一 is ichi, one; 日 is nichi, day or sun. Read ichinichi, it means a span of one day. The same kanji read tsuitachi mean the first of the month, so the reading tells you duration versus date.
一 — single horizontal stroke
一 is one of the simplest pictographs in Chinese, depicting a single horizontal line to represent the number one. It has retained essentially the same form since oracle bone script over 3,000 years ago. By extension it also means 'first,' 'whole,' or 'same.'
日 — pictograph of the sun
日 is a pictograph of the sun, originally drawn as a circle with a dot or stroke inside representing the sun's substance. Over time the round shape was squared off into the modern rectangular form. It means 'sun' and by extension 'day'.
ついたち · tsuitachi · JLPT N5 · noun
day
📅 tsuitachi = tsuki + tachi: the moon sets out, so the month begins
ついたち is a contraction of 月立ち (tsuki-tachi), the moon rising or setting out, which marked day one of the lunar month. The kanji 一日 simply mean one + day; read as いちにち they mean a single day instead.
一 — single horizontal stroke
一 is one of the simplest pictographs in Chinese, depicting a single horizontal line to represent the number one. It has retained essentially the same form since oracle bone script over 3,000 years ago. By extension it also means 'first,' 'whole,' or 'same.'
日 — pictograph of the sun
日 is a pictograph of the sun, originally drawn as a circle with a dot or stroke inside representing the sun's substance. Over time the round shape was squared off into the modern rectangular form. It means 'sun' and by extension 'day'.