by the day   (TTS發音)

according to the number of days given to work 按日（計工等）

    They are paid not by the day but by the month. 他們是按月而不是按天計酬的。

    The secretary works so hard that her working time can hardly be counted by the day. 這位秘書工作十分努力，她的工作時間很難按天數來計算。