day after day 与 day by day 与 day and day 有和不同

day after day
adv.
日复一日(=day by day)

day by day
adv.
逐日

day and day
一天又一天

day after day 日复一日[没有变化，有略微的贬义]
The farmers are working on the farm day after day.

day by day 逐日地[可以反映出事物的渐变过程]
He grows taller day by day(day after day 不合适)

没有 day and day这个词组。