adv. phr. Regularly; consistently; all the time; always. He plays good tennis day in and day out. Also used with several other time words in place of day: week, month, year. Every summer, year in, year out, the ice cream man comes back to the park.
DAY IN AND DAY OUT
Meaning of DAY IN AND DAY OUT in English
American idioms English vocabulary. Английский словарь американских идиом. 2012