for days/weeks etc on end
From Longman Dictionary of Contemporary Englishfor days/weeks etc on endfor days/weeks etc on endCONTINUOUSfor many days, weeks etc without stopping He was tortured for days on end. endExamples from the Corpusfor days/weeks etc on end Untouched, and for days on end, ignored, he was not a child and not a man. Lately she stays in her house for days on end, goes out only to get food. How you hate being shipped off to Long Island for weeks on end during the summer. He would go off into the mountains for days on end. Big dumps frequently bury lift-control shacks and loading ramps for days on end. Sometimes he would not leave his room for days on end. Chained in an upright stance for weeks on end, iron collars about their necks, with no hope of reprieve. They'd be talking for days on end.