"Congratulations" is a song recorded by K-pop boy band Day6 for their debut EP The Day. The song served as the group's debut single in September 2015 and was the first and last single to include Junhyeok before his departure in February 27, 2016.
On September 7, 2015, both "Congratulations" and their first EP The Day were released.
The music video shows a man remembering the memories with his beloved lover and struggling after the break up. It features actors Choi Woo-sik, Jang Hee-ryung and Kang Yoon-je who are in a love triangle.
The music video was directed by Naive Creative Production.
"Congratulations" lyrics were written by all Day6 members and composed by Day6, Hong Ji-sang and Lee Woo-min. The song is composed in the key E-flat Major and has 180 beats per minute and a running time of 3 minutes and 49 seconds. The song is described as honestly expressing the last words to a lover who has another person.