質問: 8時に起きる と 8時で起きる はどう違いますか? 8時に起きる と 8時で起きる はどう違いますか?
回答: you could say both. normally you say 8時に but there could be a occasion to say 8時で. in such case it might sound like, you stop sleeping at 8. like sleeping time is over 8. when ppl get up it’s almost always に though. so i suggest, to make your life easier, you can remember 8時<に> only and forget about the rest.