每天;时常
If something changes (from) day to day, it changes often.
The symptoms of the disease change from day to day. 这种疾病的症状每天都会发生变化。
The price of this commodity fluctuates from day to day.
Weather conditions here change dramatically day to day.
The number of appointments available varies day to day.
The options on the menu will differ from day to day, based on what the latest farm delivery contains.
See also: day