pydata/pandas — pull request #8549 by mtkni (2014-10-13 16:14:02+00:00)
Title: PERF: Slowness in multi-level indexes with datetime levels (part 2)

Corrects some deficiencies noted here: https://github.com/pydata/pandas/pull/8544#issuecomment-58909397. Adds a test case and an additional vbench test.