Conversation so far:
When did Ruhollah Khomeini return to Iran from exile?
On Thursday, 1 February 1979, Ruhollah Khomeini returned to Iran.
What happen to Ruhollah Khomeini after returning to Iran?
Ruhollah Khomeini was welcomed by a joyous crowd estimated to be of up to five million people.
Did Ruhollah Khomeini do anything else important after returning to Iran?
On 11 February, Ruhollah Khomeini appointed his own competing interim prime minister, Mehdi Bazargan to Shapour Bakhtiar.

Question: What year did he do that?
Self-contained rewrite: What year did Ruhollah Khomeini appoint his own prime minister?