:Agreed, but it's the date that needs changing - using the 1979 Jubilee Line logic, the H&C; & ELL should both be in the 1980s, which is when they became known by those names. Finchley Rd to Willesden Green opened in 1879, so I'm changing the date to that, & clarifying the definition to "the date the first section opened (not necessarily under the current line name)", which is the definition that seems to have been used for other lines' dates.