Over the span of their career, Girl's Day has endorsed over 20 brands, including LG Electronics, Ezaki Glico's Pocky, Lotte World, Nexon and Bullsone.

The group released Girls' Day Party #4 in September, with the track "Don't Flirt" ("너, 한눈 팔지마!").

[7] The remaining four members returned with the song "Don't Forget Me" ("나를 잊지마요") from Girl's Day Party #5.

On January 3, 2014, Girl's Day released their fourth EP, Everyday 3, which was largely produced by Duble Sidekick.

The song also ranked first on the monthly Gaon Digital Chart, and remained in the top 10 of the Korea K-Pop Hot 100 for eight weeks.

[5] In July, the group released their fifth EP, Everyday 4, with the lead single "Darling", which ranked 27th on Melon's digital annual chart.

[12] Girl's Day released their second full-length album Love, along with its title track "Ring My Bell", in July 2015.

[13] During promotions for the album, the group faced controversy over their July 7 appearance on a Korean internet-streamed program, ChoiKoon TV.

[16] On March 2, 2017, Dream T Entertainment announced that Girl's Day was set to comeback after 21-month long hiatus during which the members focused on solo activities.

The agency revealed that the group is in the process of wrapping up recording for their title track, and the comeback was set for late March 2017.

[18] On March 17, Dream T Entertainment released the group's comeback schedule and revealed that the new album would be the fifth part of the "Everyday" series.

[22] On January 11, 2019, it was reported that all of the members would not re-sign with Dream T Entertainment and they would join separate agencies while not officially disbanding.

[28] The entire proceeds from the group's concert in 2014 were donated to support the birth registration of girls in developing countries.

[29] In February 2016, Sojin and Yura represented Girl's Day as Plan Korea ambassadors in Cambodia, volunteering at a school where they held art and music workshops.