I am new to Elixir and trying to run some scripts from elixir documentation, testing Date structure gave a strange result because
Date.compare(~D[2016-04-16], ~D[2016-04-28]) is returning :lt
while when trying to run Date.diff(~D[2016-04-16], ~D[2016-04-28]) I am getting this error
(UndefinedFunctionError) function Date.diff/2 is undefined or private
(elixir) Date.diff(~D[2016-04-16], ~D[2016-04-28])