何なん日にちも

adverb

for many days; for several days

Emphasizes that an action or state continues over a period of multiple days, often with a sense of 'day after day'.

• 彼かれは何なん日にちも家いえに帰かえらなかった。

  He didn't come home for many days.

• 何なん日にちも雨あめが降ふり続つづいている。

  It has been raining for days.