When the last day of registration is, let's say, 15 July, we currently say "please confirm your registration before 16 July" but students often send their confirmation on 16 July, rather than 15. I guess it's the date itself that's misleading.
English Language & Usage Stack Exchange is a question and answer site for linguists, etymologists, and serious English language enthusiasts. It's 100% free, no registration required.
Here's how it works:
- Anybody can ask a question
- Anybody can answer
- The best answers are voted up and rise to the top
As in the comments, a common form that is succinct yet unambiguous is:
Another unambiguous option is: