The song received positive reviews from music critics. Yahoo! reviewer Jackie Flynn wrote that the song was a "slick piece of dominatrix dance" with "big buffed chords and spike-heel beats".^[1] Peter Robinson of NME described "Day & Night" as "exciting" and the magazine wrote that the song was "somewhat harder and American sounding" than her previous singles.^[2][3]

"Day & Night" debuted on the UK Singles Chart on 21 May 2000 at number one.^[4] It remained on the chart for 13 weeks before exiting the top 100 in August 2000. In May 2000, the single was certified silver by the BPI.^[5] This was Piper's third and final chart-topper in the UK—jointly the most achieved by a British female artist at this point. The track also reached the top 20 in Ireland and the top 50 in Flanders and the Netherlands.^[6][7][8] In Australia, "Day & Night" debuted on the ARIA Singles Chart on 4 June 2000 at number 16. Eight weeks later, the song peaked at number eight.^[9] The track debuted in New Zealand on 4 June 2000 at number 43. It peaked at number six three weeks later and remained on the chart for 15 weeks.^[10]

The music video for "Day & Night" was directed by Cameron Casey.^[11] It features Piper dancing at a nightclub with a group of friends. The video begins with Piper and three friends walking down a street at night, looking for an exclusive nightclub. After being allowed in, Piper and a group of male dancers begin to perform a dance routine. She is then shown dancing with a group of female dancers on a brightly lit street. The third scene features Piper dancing in a pink room. The video concludes with Piper and her dancers in a laundrette, dancing on top of washing machines and throwing washing powder around the room. The video premiered in the UK on 9 March 2000.^[3]

UK CD1 and Australasian CD single^[11]

1. "Day & Night" (Stargate mix) – 3:15
2. "Day & Night" (Almighty Club mix) – 8:04
3. "Day & Night" (Robbie Rivera's Bombastic vocal mix) – 7:05
4. "Day & Night" (video)

UK CD2^[12]

1. "Day & Night" (Stargate mix) – 3:15
2. "Tinted Eyes" – 3:57
3. "Day & Night" (Friday Hope mix) – 7:13

UK and New Zealand cassette single^[13]

A1. "Day & Night" (Stargate mix) – 3:15

A2. "Honey to the Bee" (Hex Hector mix) – 4:32

B1. "Day & Night" (Sleaze Sisters anthem) – 6:40

Credits are lifted from the UK CD1 liner notes.^[11]

Studio

• Recorded and mixed at StarGate Studios (Norway)

Personnel