The calendar sees the return of races in Bahrain and Brazil, with the Middle Eastern event moving from six to eight hours in length. In total there are two 4-hour races (Silverstone and Shanghai), three 6-Hour races (Fuji, Sao Paulo and Spa-Francorchamps, two 8-hour races (Bahrain and Sebring*) and the biggest race in the world, the 24 Hours of Le Mans, concludes the 8th season of the FIA WEC since it began in 2012.
https://www.fia.com/news/wec-20192020-fia-wec-calendar-approved
2019-2020 FIA World Endurance Championship Calendar
Rd 1 01 September 2019 4 Hours of Silverstone GBR
Rd 2 06 October 2019 6 Hours of Fuji JPN
Rd 3 10 November 2019 4 Hours of Shanghai CHN
Rd 4 14 December 2019 8 Hours of Bahrain BHN
Rd 5 01 February 2020 6 Hours of São Paulo BRA
Rd 6 March 2020 1000 Miles of Sebring (8 hours) USA (TBC)
Rd 7 02 May 2020 6 Hours of Spa-Francorchamps BEL
Rd 8 13-14 June 2020 24 Hours of Le Mans FRA