Timestamp timezone inconsistency

[cyber42]

Hi,

Is this a known issue?

Time offset on 22nd of Sept should be -4 hours in New York as below:

pandas.Timestamp('2014-09-22 09:30:00-0400', tz='EST5EDT').tz_convert('EST5EDT')
Timestamp('2014-09-22 09:30:00-0400', tz='EST5EDT')

but when providing this twice (-0400 and EST4EDT), the result becomes -0500:

pandas.Timestamp('2014-09-22 09:30:00-0400', tz='EST5EDT')
Timestamp('2014-09-22 08:30:00-0500', tz='EST5EDT')

Thanks,
Mark

INSTALLED VERSIONS

commit: None
python: 2.7.6.final.0
python-bits: 64
OS: Linux
OS-release: 3.13.0-37-generic
machine: x86_64
processor: x86_64
byteorder: little
LC_ALL: None
LANG: en_GB.UTF-8

pandas: 0.14.1
nose: 1.3.0
Cython: 0.19.2
numpy: 1.8.1
scipy: 0.13.2
statsmodels: 0.5.0
IPython: 2.0.0
sphinx: None
patsy: 0.2.1
scikits.timeseries: None
dateutil: 2.2
pytz: 2014.2
bottleneck: 0.8.0
tables: 3.0.0
numexpr: 2.3
matplotlib: 1.3.1
openpyxl: None
xlrd: None
xlwt: None
xlsxwriter: None
lxml: None
bs4: None
html5lib: 0.999
httplib2: 0.8
apiclient: None
rpy2: None
sqlalchemy: None
pymysql: None
psycopg2: None

[jreback]

These all represent exactly the same time
you also have a pytz that maybe doesn't have the correct offsets (you are using 2014.2)
mine is 2014.7 the most recent.

In [10]: Timestamp('2014-09-22 08:30:00-0500', tz='EST5EDT').tz_convert('UTC')
Out[10]: Timestamp('2014-09-22 13:30:00+0000', tz='UTC')

In [11]: pandas.Timestamp('2014-09-22 09:30:00-0400', tz='EST5EDT').tz_convert('UTC')
Out[11]: Timestamp('2014-09-22 13:30:00+0000', tz='UTC')

In [12]: pandas.Timestamp('2014-09-22 09:30:00-0400')                                
Out[12]: Timestamp('2014-09-22 09:30:00-0400', tz='pytz.FixedOffset(-240)')

In [14]: pandas.Timestamp('2014-09-22 09:30:00-0400').tz_convert('UTC')
Out[14]: Timestamp('2014-09-22 13:30:00+0000', tz='UTC')

[rockg]

This works fine for me as well. So either check with pandas master or an updated pytz (although I would find the latter really hard to believe since there is nothing special with this offset).

pd.Timestamp('2014-09-22 09:30:00-0400', tz='EST5EDT')
Out[35]: Timestamp('2014-09-22 09:30:00-0400', tz='EST5EDT')

[jreback]

actually I think this was #7833 which was fixed for 0.15.0

[cyber42]

Great, thanks! Didn't realize RC is the stable version now.

Yes, they both represent the right UTC time, but one of them didn't have
the rigth offset of its timezone, EST5EDT.
On 28 Oct 2014 01:38, "jreback" [email protected] wrote:

actually I think this was #7833
#7833 which was fixed for 0.15.0

—
Reply to this email directly or view it on GitHub
#8656 (comment).

[rockg]

I wouldn't call RC the stable version (however it is pretty stable and everything that gets merge needs to pass all the tests). v0.15.0 is the latest release and this is fixed there.

[jreback]

0.15.0 is the stable version released that week

http://pandas.pydata.org/pandas-docs/stable/whatsnew.html