Part of the London Overground ( Highbury and Islington to New Cross ) should begin Night Tube service by 2017 , while the sub-surface lines and Docklands Light Railway are planned to begin Night Tube services in 2021 .
Part of the London Overground ( Dalston Junction to New Cross Gate ) are scheduled to begin Night Tube services in December 2017 , with a planned extension to Highbury and Islington in 2018 . 
 The Docklands Light Railway is planned to begin Night Tube services in 2021 .