date_range bug?

[xdong]

If 'start' is a timezone-aware datetime.datetime or Timestamp, then it will get shifted by several hours.

In [1]: from pandas import *

In [2]: start = Timestamp('20130220 10:00', tz='US/Eastern')

In [3]: start
Out[3]: <Timestamp: 2013-02-20 10:00:00-0500 EST, tz=US/Eastern>

In [4]: dr = date_range(start, periods=2)

In [5]: dr
Out[5]: 
<class 'pandas.tseries.index.DatetimeIndex'>
[2013-02-20 15:00:00, 2013-02-21 15:00:00]
Length: 2, Freq: D, Timezone: US/Eastern

In [6]: dr[0]
Out[6]: <Timestamp: 2013-02-20 15:00:00-0500 EST, tz=US/Eastern>

It seems that start' time component was treated as if it's UTC by date_range.

[Moisan]

date_range permits to include the timezone with the "tz" arguments like this: dr = date_range(start, periods=2, tz='US/Eastern'). However this fails with an assert that the inferred timezone is not the same as the given timezone. So I suppose the inferred timezone is wrong.
Edit: this seems like a deeper problem unrelated to this issue. I opened a new issue for that.

[stephenwlin]

PR #2935 should do it