About 1,2,3 dayz up (feat. SOPHIE)

"1, 2, 3 Dayz Up" (stylized as "1,2,3 dayz up") is a song by German singer-songwriter Kim Petras featuring Scottish producer Sophie. It is the final of eleven singles that form Petras' unofficial project Era 1. The song was produced by Sophie, Dr. Luke and Aaron Joseph, and was written by them along with Petras and Aaron Jennings. The track's official lyric video was released on 13 February 2019.

Prior to the release, Sophie premiered the song as "We Don't Stop" at Form 2018. The track was officially released on February 8 alongside the songs "If U Think About Me..." and "Homework" featuring Lil Aaron. The song was composed in the D-flat major key at 108 beats-per-minute and is 3 minutes and 33 seconds long. The track was Petras' first release since her Halloween-themed EP Turn Off The Light, Vol. 1 (2018).