The audience loved Yueming's amazing performance as the twin brothers in Day and Night. There has been a running joke on the internet that Yueming has a twin brother in real life named Yue'an who acted the younger brother in the show (in Chinese, "Ming" means "bright" while "An" means "dark".)
The audience were also curious that whether Yueming earned twice of the salary since he played two roles as the twin brothers in the show. The director Wang Wei joked in an interview that there was no double pay but double box lunches for Mr. Pan.
During the shooting, the crew helped Wang Longzheng (Zhou Xun) plan a secret proposal ceremony to his long-term girlfriend Ma Wei (Ren Di). Ma Wei was told they needed to do one more extra scene and followed the play script to watch a video together with Wang Longzheng. After a while, it turned into their past sweet moments in the video. Then Wang Longzheng proposed with a ring and flowers.
In the show, the younger brother was wearing the same clothes and had the same hair style while he was pretending to be his elder identical twin brother. This arrangement made them completely identical, which was necessary since the younger brother had to work as the older brother in the police station among a bunch of detectives. However, the audience could still immediately distinguish one from the other through the actor Yueming's subtle facial expressions, body language, tone of voice, and eye expressions.
The script writer of Day and Night - Zhiwen (which means "fingerprint" in Chinese) had ever worked as a professional lawyer for 11 years. That is why he has been familiar with the procedure of criminal investigation, interrogation, forensic science, prosecution and defense and therefore is able to write a script of Day and Night full of authentic details.