Comprehensive resource for understanding and mastering English idioms
The idiom "day in, day out" means that something is done or experienced every day, without any breaks or variation. It can be used to describe a routine or a task that needs to be completed daily.
The idiom "day in, day out" has been used in English since the 16th century. It comes from the phrase "day by day", which means each individual day. Over time, the phrase evolved into "day in, day out", indicating that something is done every single day without any breaks or variation.