I'm sorry -- I just now saw your post!
I believe there are now over 70,000 registered daylilies. Add in that many hybridizers sell the seedlings that they don't want.... so there are a LOT of daylilies on the market. Many, many of them look alike.
Once in a while someone will post a photo of a "No ID" that has some distinguishing characteristic and we can take a guess --- but even then it's just a guess. You can never know for sure.
With one like you have - there are many that it could be.
If you had a list of ones you bought at nursery, for example, and didn't know which one this was - well then we might have a chance at ID --- but to know from the photo --- there are just to many that it could be.
I think it is always best to keep a plant unidentified than to guess at a name when you can't be sure.
My advice is to enjoy it and consider it to be "that red one from the neighbor..."