day in day out
US /deɪ ɪn deɪ aʊt/
UK /deɪ ɪn deɪ aʊt/

1.
日復一日, 每天
continuously or repeatedly over a long period of time
:
•
He does the same boring job day in day out.
他日復一日地做著同樣無聊的工作。
•
The factory produces thousands of units day in day out.
這家工廠日復一日地生產數千件產品。