[Numpy-discussion] casting from datetime64

Hi, When registering a custom cast function from datetime64 to another dtype, how can I get the units? I am calling PyArray_RegisterCastFunc from NPY_DATETIME. Ideally, I'd like to register a separate cast function for each datetime64 units (or none at all... I don't want all units to be castable). Next best thing would be to obtain the units in the cast function and dispatch accordingly. Is this possible? I glanced through the code, and it looks like there's a lot of hard-coded logic around datetime64, but I didn't go through it carefully. Thought I'd ask before drilling further down. Thanks in advance, Alex