by day

by day
日间，在白天
Day by day she learnt more about her job.
她日益了解自己的工作了。
The fugitives travelled by night and rested by day.
逃亡者夜行而昼伏。
What is done by night appears by day.
若要人不知除非己莫为。
Owls sleep by day and work at night.
猫头鹰白天睡觉晚上工作。
The patient's condition is improving day by day.
病人的病情逐日好转。
You can see stars by night, but not by day.
你在夜晚可以看到星星，白天却看不到。