Direct path for np.ndarray <- pd.Series
Break out tests based on units
Refactor numpy datetime truncate code to use an offset relative to python definition of start
Simplify offsets code
Use view rather than astype to avoid a copy
Clarify offsets code even moar!
Last bit o' whitespace
Note about use of D unit in week calculations
Merge pull request #882 from cpcloud/datetime-truncation

Fix datetime truncate for day period