In other examples “dong an” is translated as “for.” In this example it uses “during.” Some consistency please.
It can mean both. 동안 is used to express a period of time, either "for (a duration)" or "while/during" - for a week, during the last week.
I would find it difficult to argue that "last" and "final" are not synonymous, though "last" is not accepted. Flagged...
Can someone clarify which word means last/final and which means last/prior? Or can 마지막 be used for either?
마지막 means last/final. It cannot be used as last/prior. You would use 지난 for that meaning.
I wrote "what did the horse do on the weekend" I think it should be accepted right?