From Dragon Ball Encyclopedia, the ''Dragon Ball'' wiki
Planet Shirts (シャーツ 惑星, Shātsu Wakusei) is a planet in the North Galaxy. It is known as Shikk in the Funimation Dub.
Planet Shirts was the homeworld of the Shirts. Vegeta, Nappa, and Raditz conquered for Freeza. According to Freeza, Planet Shirts was a small planet and Zarbon estimated that it would have taken him only a full day to conquer it, while it took the three Saiyans three days to do so.