Seven O'Clock released their debut mini-album Butterfly Effect and its lead single "Echo" on March 16, 2017.

[3] On September 19, 2018, it was announced via their fan café that Vann had left Seven O'Clock, and that the group would now be managed by Forest Network.

[8] On October 4, Forest Network announced the addition of two new members, Rui and Eungyul, while also stating that Jeonggyu, Hyun, and 2Soul would be going on a temporary hiatus to focus on their health.

[10] On October 18, Forest Network announced that Eungyul would not be taking part in Seven O'Clock activities for personal reasons.

[12] On August 29, 2020, Seven O'Clock released their 5th project album Highway with the lead single "Hey There".