The idiom day in, day out is used to describe something that happens routinely or regularly, so the entailment is that it is something that happens on a daily basis.
Consider the statement "Mr mcelroy, its pretty hard to deal with on a daily basis in a marriage.". Based on this "Mr mcelroy, its pretty hard to take day in, day out in a marriage." a true statement? Yes, no, or I don't know?