| Book of Days | |
| Type: | studio |
| Artist: | Nektar |
| Cover: | Book of Days (Nektar album).jpg |
| Released: | 16 May 2008 |
| Genre: | Progressive rock |
| Length: | 54:47 |
| Label: | Bacillus |
| Prev Title: | Evolution |
| Prev Year: | 2004 |
| Next Title: | A Spoonful of Time |
| Next Year: | 2012 |
Book of Days is the eleventh studio album by the progressive rock band Nektar, released in 2008. It saw the departure of founding keyboardist Alan "Taff" Freeman, leaving only two original band members in guitarist/frontman Roye Albrighton and drummer Ron Howden.[1]
For the deluxe release, Albrighton's solo album The Follies of Rupert Treacle was included.[2]