Almost every day; indicating that something happens very frequently, though not necessarily literally every single day.
彼は毎日のようにジムでトレーニングしている。
He trains at the gym almost every day.
毎日のようにメールが届いてうんざりする。
I'm fed up with getting emails almost every day.
この店は毎日のように新しい客が来る。
New customers come to this shop almost every day.