Democratic Alliance leader Mmusi Maimane has written to President Jacob Zuma asking him to declare August 16 "Marikana Memorial Day".
The date last week marked the fifth anniversary of the Marikana tragedy, where 34 mineworkers were shot and killed by members of the South African Police Service.
Another 10 had died in the week leading up to the massacre during the wildcat strike in the platinum belt.
Maimane on Wednesday said it was time to mark the occasion of the August 2012 tragedy nationally.
"I have today written to President Jacob Zuma requesting that he declare 16 August a commemorative day to be observed annually in honour of those workers who lost their lives in Marikana.
"On the day, South Africans from all walks of life joined together in paying their respects to the fallen heroes of Marikana, calling for justice for the victims, and their families and loved ones."
The Marikana tragedy remained a stain on the collective conscience of the nation, he said.
"We must mark this day as a commemorative one, where we reflect not just on the injustice of that fateful day, but the injustices which still persist throughout our society."
Maimane said the president has the power to declare any day to be observed and commemorated via a proclamation.
"We are not alone in this call. We are joined by many in society, including political parties and trade unions who also believe this day ought to be declared as such."