明明後日
しあさって · shiasatte · JLPT N2 · noun
tomorrow
📅 明 (tomorrow) + 明後日 (day after tomorrow) = two days after tomorrow
The first 明 means tomorrow, stacked onto 明後日, the day after tomorrow. Each 明 adds one more day ahead, so the word reaches two days out.
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'.