"좋은 하루 되세요" It is an expressions influenced from English. I recommend you to use Korean style expressions.

＠Chopin I agree with you. Many of the Koreans say 좋은 하루 되세요 a lot. But it's not that a few Korean people say 좋은 하루 보내세요 so I think Korean learners should be informed what's exactly that for an English expression in Korean. Then they can choose what they will say between 좋은 하루 되세요(many Koeans say this way, but it's incorrect) and 좋은 하루 보내세요(it's correct even if many Korean people seem to say 좋은 하루 되세요) My point is just this.

＠Chopin 좋은 하루 보내세요 is correct.

Thanks Hailey. Increasingly more expressions are borrowed from English, and many of them are not natural in Korean culture. I wish that people (especially Korean learners) use more Korean style expressions.