Day in day out every day without fail phrase.
"Day in, day out, every day without fail" means something that happens on a daily basis
She is so devoted to music that she practices singing and playing musical instruments day in, day out, every day without fail after school
My brother is a soldier who wakes up at 5 am and does physical exercise day in, day out, every day without fail.
I go to school late, day in, day out, every day without fail.
Very frequently and predictably.
This phrase is used based on its literal meaning.
To not get any sleep at all
I'm so tired! I have not slept one wink last night.