Conversation so far:
when did Ruhollah Khomeini die?
Ruhollah Khomeini died on 3 June 1989.
how did he die?
after suffering five heart attacks in just ten days.
what happened in 10 days?
After spending eleven days in Jamaran hospital, Ruhollah Khomeini died on 3 June 1989 after suffering five heart attacks in just ten days.
how old was he when he died?
died on 3 June 1989 after suffering five heart attacks in just ten days, at the age of 86.

Question: when was his funeral?
Self-contained rewrite: When was Ruhollah Khomeini's funeral?