Student or Learner
"He had a break between each hour."
Should "each hour" be replaced with "hours", since "between" seems to suggest two things?
Self-Cleaning Public Toilets Yield to Older Technology in Manhattan - NYTimes.com
"Besides, the toilets were a beast and an expense to maintain. Annoyingly, they needed a two-minute break between each user for the nozzles and sprays to do their thing."
Should "between each user" be replaced with "between users"?
You could make an argument that it is wrong though. For example, "Doctors should wash their hands between each patient". This means, strictly, that they should wash their hands between Mr Smith, and then between Mr Jones ..., which is absurd. It's this absurdity that rules out any ambiguity and makes it alright. (So, I would argue).