10,000 Days is the fourth studio album by American rock band Tool, released in 2006. It followed Lateralus (2001) and was the band's first studio album in five years. The album combines progressive metal, alternative metal and psychedelic influences with complex rhythms, extended compositions and the band's characteristic use of unconventional time signatures.
The album includes the singles “Vicarious”, “The Pot” and “Jambi”, as well as the two-part composition “Wings for Marie (Pt 1)” and “10,000 Days (Wings Pt 2)”. The latter pair was inspired by the life and death of vocalist Maynard James Keenan's mother, Judith Marie Keenan, who lived with paralysis for approximately 27 years following a cerebral aneurysm. Roughly 27 years corresponds to 10,000 days, giving the album its title.
Musically, 10,000 Days continued the progressive direction of Lateralus while placing greater emphasis on heavy guitar riffs, polyrhythms and long-form compositions. Danny Carey's drumming and Justin Chancellor's bass playing are particularly prominent throughout the album, while guitarist Adam Jones contributed both to its musical arrangements and visual presentation.
The album's packaging featured stereoscopic artwork and a pair of built-in lenses through which the illustrations could be viewed in three dimensions. The visual design incorporated artwork by Alex Grey, who had previously collaborated with Tool on Lateralus. The packaging won the Grammy Award for Best Recording Package.
10,000 Days was commercially successful and reached number one on the Billboard 200 in the United States. “Vicarious” and “The Pot” became among Tool's best-known songs, while the album remained the band's final studio release for thirteen years, until Fear Inoculum appeared in 2019.