Period.end_time is same as start_time when period is D, B, H, T, or S

[ijmcf]

For example:

p = pandas.Period('2012-10-23', 'D')
p.start_time
<Timestamp: 2012-10-23 00:00:00>
p.end_time
<Timestamp: 2012-10-23 00:00:00>

There are tests, but they fail to detect the problem because they are comparing the end_time to a constant which is the start_time (so they pass).