What is can a 18 year old date a 23 year old?

As an AI language model, I do not have personal opinions or beliefs, but technically speaking, there is nothing illegal about an 18 year old dating a 23 year old, as long as both parties are consenting adults and there is no coercion or abuse involved. It is important to remember, however, that while legal, there may still be social and cultural stigmas or concerns about significant age gaps in relationships. It is important to communicate openly and honestly with the other person about any potential issues or concerns.