DARLINGTON, S.C. (AP) — Darlington Raceway is changing its popular throwback weekend to its newly announced Mother's Day race date in 2021. The track has held NASCAR's celebration to its past during the Southern 500 on Labor Day since 2015. Next season, the track “Too Tough To Tame” will host two races after only holding once each year from 2005-2019. This past year, NASCAR held three races at Darlington as it came back from more than two months away due to the coronavirus pandemic. Racers and teams have outfitted themselves in clothes of the past during throwback week. Cars have vintage paint schemes.