Indices zero based or one based?

Are indices in the Intel MKL BLAS and LAPACK function zero-based or one-based. For example the function idamax I think returns a zero-based argument with MKL CBLAS. However, my experience with Netlib was that this returned a one based index. There are also other functions such as dsyevx that require index arguments and I don't know whether these should be one-based or zero-based.