A week is a time unit equal to seven days. The English word week continues an Old English wice, ultimately from a Common Germanic *wikōn-, from a root *wik- "turn, move, change". The Germanic word probably had a wider meaning prior to the adoption of the Roman calendar, perhaps "succession series", as suggested by Gothic wikō translating taxis "order" in Luke 1:8. The term "week" is sometimes expanded to refer to other time units comprising a few days. Such "weeks" of between four and ten days have been used historically in various places. Intervals longer than 10 days are not usually termed "weeks" as they are closer in length to the fortnight or the month than to the seven-day week.

Evidence of continuous use of a seven-day week appears with the Jews during the Babylonian Captivity of the 6th century BC. Both Judaism (based on the Creation narrative in the Bible) and ancient Babylonian religions used a seven-day week. Other cultures adopted the seven-day week at different times. Between the 1st and 3rd centuries the Roman Empire gradually replaced the eight-day Roman nundinal cycle with the seven-day week. Hindus may have adopted a seven-day week earlier than 11th century BC.^{[citation needed]} See Rig Veda. There is evidence of some Chinese groups using a seven-day week as early as 4th century.

Leona Louise Lewis (born 3 April 1985) is a British singer and songwriter. Lewis came to prominence in 2006 when she won the third series of the British television series The X Factor.

Lewis has released two albums to date, Spirit and Echo, in 2007 and 2009 respectively. A multi-platinum selling artist and three-time Grammy Award nominee, her most successful single, "Bleeding Love", reached number one in over thirty countries around the world, and was the best-selling single worldwide in 2008. Other notable singles include "Better in Time", "Happy" and "I Got You". She was proclaimed 'Top New Artist' by Billboard magazine in 2008.

Lewis's debut tour, The Labyrinth, took place in 2010, and her third album, Glassheart, is scheduled for release in 2012. It was preceded by "Collide", a single from the album, which became her seventh top-five hit in the United Kingdom. Lewis's net worth was estimated at £12 million in April 2012.

Peter Gene Hernandez (born October 8, 1985), better known by his stage name Bruno Mars, is an American singer-songwriter and record producer. Raised in Honolulu, Hawaii by a family of musicians, Mars began making music at a young age. He performed in various musical venues in his hometown throughout his childhood. He graduated from high school and then moved to Los Angeles, California to pursue a musical career. Mars produced songs for other artists, joining production team The Smeezingtons.

Mars had an unsuccessful stint with Motown Records, but then signed with Atlantic Records in 2009. He became recognized as a solo artist after lending his vocals and co-writing the hooks for the songs "Nothin' on You" by B.o.B, and "Billionaire" by Travie McCoy. He also co-wrote the hits "Right Round" by Flo Rida featuring Ke$ha, and "Wavin' Flag" by K'naan. In October 2010, he released his debut album, Doo-Wops & Hooligans. Anchored by the worldwide number-one singles "Just the Way You Are" and "Grenade", the album peaked at number three on the Billboard 200. Mars was nominated for seven Grammys at the 53rd Grammy Awards, winning Best Male Pop Vocal Performance for "Just the Way You Are".

Edward Christopher "Ed" Sheeran (born 17 February 1991) is an English singer-songwriter who is currently signed to Asylum / Atlantic Records. Sheeran broke through commercially in June 2011, when his debut single "The A Team" debuted at number 3 on the UK chart.

Sheeran was born in Halifax, West Yorkshire to Irish and English parents, before moving to Framlingham, Suffolk; he is a cousin of TV journalist and presenter Gordon Burns. He learned guitar at a very young age, and began writing songs during his time at Thomas Mills High School in Framlingham. His early childhood memories, referred to in a interview on the Zane Lowe show, included listening to Van Morrison on his countless trips to London with his parents and going to an intimate gig with Damien Rice in Ireland when he was 11. He also opened for Nizlopi in Norwich in April 2008 after being one of their guitar technicians. Sheeran began recording in 2005, which led to the release of his first EP, The Orange Room EP. Sheeran also released 2 albums, a self-titled one in 2006 and Want Some? in 2007. He moved to London in 2008 to play gigs, starting off in very small venues, playing every day, to as little as five people. In 2008, he auditioned for the ITV series Britannia High.

Mariah Carey (born March 27, 1970) is an American singer, songwriter, record producer, and actress. She made her recording debut in 1990 under the guidance of Columbia Records executive Tommy Mottola, and released her self-titled debut studio album, Mariah Carey. The album went multi-platinum and spawned four consecutive number one singles, on the U.S. Billboard Hot 100 chart. Following her marriage to Mottola in 1993, a series of hit records, including Emotions (1991), Music Box (1993) and Merry Christmas (1994), established her position as Columbia's highest-selling act. Daydream (1995), made music history when the second single, "One Sweet Day" a duet with Boyz II Men, spent a record sixteen weeks on top of the Billboard Hot 100, and remains the longest running number one song in US chart history. During the recording of the album Carey began to deviate from her pop background, and slowly traversed into R&B and Hip-hop. After her separation from Mottola, this musical change was evident with the release of Butterfly (1997).