It will be lights out at landmarks across Hounslow as the borough remembers those who gave their lives in the First World War.
Chiswick Town Hall, Hounslow Civic Centre and Hanworth Air Park Leisure Centre are among the public buildings due to descend into darkness between 10pm and 11pm on Monday, August 4.
Businesses and residents across the borough have been urged to join the switch-off, taking place on the 100th anniversary of the day Britain joined the conflict.
Deputy Hounslow Council leader Amrit Mann said: "The LIGHTS OUT campaign is a poignant reminder of the ultimate sacrifice paid by hundreds of thousands during the First World War. The council will be turning its LIGHTS OUT at the Civic Centre and other buildings and I would invite residents to also take part in this special campaign."
Millions of people across the UK are expected to participate in the blackout, during which they are invited to leave a single light or candle burning, as they unite in reflection on the sacrifices made all those years ago.
The LIGHTS OUT project is being organised as part of 14-18 NOW, the official cultural programme for the First World War centenary commemorations.
It was inspired by the words of then foreign secretary Sir Edward Grey, who said: "The lamps are going out all over Europe; we shall not see them lit again in our life-time."
The buildings taking part in LIGHTS OUT in Hounslow include:
Hounslow Civic Centre
Chiswick Town Hall
Boston Manor House
Brentford Fountain Leisure Centre
Isleworth Leisure Centre
Osterley Sports and Athletics Centre
Hanworth Air Park Leisure Centre
* For details about LIGHTS OUT events in your area you can search the LIGHTS OUT map at www.1418NOW.org.uk/lightsout