Efter endnu en dag is their most ambitious and sophisticated album. The bombastic rock of Stakkels Jim and Gas 5 was replaced by a more eclectic approach making this album their Sgt. Peppers Lonely Hearts Club Band.
"Pilli villi" and "Pas på svinget i solrød" are up-tempo rock songs, while "De fem årstider" and "This Is My Life" are ballads. In between are sing-along pop hymns such as "Sirenesangen" and swing jazz songs such as "Bella Donna". "Stenalderjazz" is an instrumental played by a symphony ensemble and not by Gasolin'. It was arranged by Palle Mikkelborg. The title song and "De gule enker" would surface again on Killin' Time as "Closer" and "Magic Garden". "This Is My Life" can be heard in an up-tempo rock version on Kim Larsen's Kim Larsen og Yankee drengene (1978) and Live i Skandinavien (1978).
Efter endnu en dag was not well received by the critics who accused Gasolin' of delusions of grandeur, but the album attained platinum confirming their superstar status in Denmark. It was engineered by Freddy Hansson and recorded in Sweet Silence Studio in Copenhagen and Trente Mølle in Funen. From this album "Sirenesangen" / "De gule enker" and "Pas på svinget i solrød" / "Bella Donna" were released as singles.
Efter endnu en dag was released on CD in 1987 with Gas 5 but due to lack of space, "Mama Cucu", "Twilight Birds", and "Stenalderjazz" were omitted. In 1991 it was remastered for CD and it is also included on The Black Box (2003). Efter endnu en dag was released in Spain as Al cerrarse un nuevo dia with song titles in Spanish translation, but sung in Danish.
Note: M. Mogensen, D. Beck and M. Moloney co-wrote the lyrics with Gasolin'.