日に日に
Meanings
1
Describes a gradual change or progression that happens each day. Often used with verbs of change like 変わる, 増える, 成長する.
It's getting warmer day by day.
His Japanese is improving day by day.
2
archaic
Archaic use meaning 'every day' or 'daily'. In modern Japanese, 毎日 or 日々 is used instead.
In old texts, 日に日に can be used to mean 'every day'.
Usage patterns
- 日に日に〈形容詞〉くなるto become increasingly ~ day by day
Now that it's autumn, it's getting colder day by day.
- 日に日に〈動詞〉ていくto keep doing ~ more and more each day
The baby is growing bigger day by day.
- 日に日に回復するto recover a little more each day
My grandfather's health is improving day by day.