As part of the ongoing construction efforts (read: hell) around Shibuya Station, the Ginza line's tracks are set to undergo a major overhaul that will suspend service between Shibuya and Omotesando and Aoyama-Itchome and Tameike-Sanno stations on November 5 & 6 (Sat, Sun) and November 19 & 20 (also a weekend, of course).
On the affected days, Ginza line trains will continue to operate between Omotesando and Aoyama-Itchome, and Tameike-Sanno and Asakusa stations. Ginza line tickets will also be valid for travel on alternate routes, including all Tokyo Metro and Toei Subway lines, the JR Yamanote line, the Tokyu line between Shibuya and Futako-Tamagawa, and the Tobu line between Asakusa and Kita-Senju stations.
And if you plan on taking the first Ginza line train of the morning, note that the 5.08am Hanzomon line train departing from Hanzomon Station for Oshiage will instead leave from Shibuya Station at 4.59am. Above ground, lane restrictions on the left side of Meiji-dori (towards Shinjuku) between 6am and 3pm on November 5 (Sat) and 19 (Sat) are likely to cause traffic jams. If, for any reason, the construction work doesn't go ahead on those days, it'll be postponed to November 12 & 13 (Sat, Sun) and 26 & 27 (Sat, Sun).
The ultimate purpose of all this commotion is to move Shibuya's Ginza line station 130m in the direction of Omotesando, with the new station set to straddle Meiji-dori and feature both wider platforms to ease congestion and platform doors to prevent, well, you know. And when can we expect it all to be done? In 2021, after the Olympics.