Girl's Day (걸스데이) is a South Korean girl group formed by Dream T Entertainment in 2010. Girl's Day debuted originally with five members and released their first song 갸우뚱(Tilt My Head) on July 7, 2010. Two months after their debut, members Jisun and Jiin left the group due to personal reasons. The group underwent re-organization which lead to the addition of Hyeri and Yura to the group.
Following a few rounds of promotions, DreamT Entertainment announced that Jihae has left the group, leaving Girl's Day with four members—Sojin, Minah, Hyeri, and Yura.
In 2013, Girl's Day went through concept changes and released their first full-length album "Expectation", which garnered public interest domestically and internationally. The group continued to release hit songs back to back and eventually rose to fame, with the members becoming variety-show favorites.
After years of successful promotions, the members' contracts in DreamT Entertainment reached its expiration in 2019. None of the members renewed, and all four of them left the company to pursue acting in different agencies. However, DreamT Entertainment and the members themselves stand firm that the group has not yet disbanded and there is a chance that they will unite once again in the future.