Conversation so far:
when did Winnie Madikizela-Mandela die?
Winnie Madikizela-Mandela died at the Netcare Milpark Hospital in Johannesburg on 2 April 2018.
how did she die?
She suffered from diabetes and had recently undergone several major surgeries.

Question: When was her funeral?
Self-contained rewrite: When was Winnie Madikzela Mandela's funeral?