Lad tiden gå (English: Let time pass) is a 1986 science fiction novel by Danish modernist writer Svend Aage Madsen. The novel focuses on one of the central themes in Madsen's writing - the nature of time. Like most of Madsen's novels it hasn't been published in English.This novel is a typical example of the third phase in Madsen's writing that's like most of his later works is set in the town of Aarhus and has several characters that also appear in his other books (Johanna, Sverre).