I am aware that one uses "on" for dates and "at" for times.
However, when there is both -- in my case in a form or table in a web application, but it could just as well be a printed application form or something similar -- which preposition should I use?
Here's a snippet from my case:
I suppose I could just change it to "Last Change" or "Last Changed", but even so I do wonder if "at" is wrong here.
I have seen Preposition at: This invoice was issued at March 21, 2018 and Using prepositions with date and time but those don't really answer my question.