Question: when are tubes 24 hours?
Answer: Five Tube lines run a 24-hour service on Fridays and Saturdays: Victoria, Central, Jubilee, Northern and Piccadilly lines. The London Overground operates 24 hours on Fridays and Saturdays between New Cross Gate and Highbury & Islington (not including Whitechapel). Standard off-peak fares apply on the Night Tube.