expression, noun
the coming days; every day that comes
Set phrase often used in expressions like 来る日も来る日も (day after day, every single day). Emphasizes the repetitive or continuous nature of days arriving.
来る日も来る日も雨ばかりだ。
Day after day, it's nothing but rain.
来る日も来る日も同じ作業の繰り返しだった。
Every single day was a repetition of the same task.
毎日 is the standard word for 'every day' in neutral statements. 来る日 is more literary and emphasizes the arrival of days, often used in the set phrase 来る日も来る日も.
Phrase composed of 来る (くる, 'to come') and 日 (ひ, 'day'), literally 'the day that comes'. The reading くるひ is a regular combination of the verb's attributive form and the noun.