numpy/numpy — pull request #295 by mwiebe (2012-06-05 18:31:02+00:00)
Title: BUG: Add a gap in NPY_DATETIMEUNIT enum where 1.6 had the busday unit

1.7 doesn't have the business day unit, but instead provides
a separate business day API. For binary compatibility, as
experienced in Pandas use of datetime64, it's a good idea for
the numbers to stay the same.

@wesm, could you take a look and make sure this is good for Pandas?