www.wikipedia.org has the following two statements:
Post-colonial history
...
In 1964, Kenyatta became Kenya's first president.
Origins of the country's name
...
At independence, in 1963, Jomo Kenyatta was elected as the first president.[25]
Two different dates.
I looked it up in my old “The World Book Encyclopedia”,copyrighted 1982.
So I figure it should have the right date. From World Book:
“Kenya is a Republic. Its Constitution. adopted in 1963, grants the people such rights as freedom of speech and religion.”
So it looks like it became a Republic in 1963.
Obama was elected in 2008 and (allegedly) became president in 2009. Same thing?
Government
Type: Republic.
Independence: December 12, 1963.
Constitution: 1963.