pd.to_datetime("2015-11-18 15:30:00+05:30").tz_localize('UTC').tz_convert('Asia/Kolkata') returns '2015-11-18 16:30:00+0530'

[PShiw]

running "pd.to_datetime("2015-11-18 15:30:00+05:30").tz_localize('UTC').tz_convert('Asia/Kolkata')" returns following o/p

Timestamp('2015-11-18 16:30:00+0530', tz='Asia/Kolkata')

It should have returned as Timestamp('2015-11-18 15:30:00+0530', tz='Asia/Kolkata') as no daylight saving is applicable in India.

[jreback]

pls show your versions of pytz and dateutil

[PShiw]

I am using Python 3.4.3

pytz Version:- 2015.7

dateutil version :- 2.4.2

[rockg]

This is somewhat similar to #11481. As you see below, the tzinfo.utcoffset gets intepreted as 4:30 (I put in print statements to help debug) and so your subsequent operations are off. This is a bug as far as I'm concerned.

>>> pd.to_datetime("2015-11-18 15:30:00+05:30")
tzinfo.utcoffset = 4:30:00
Timestamp('2015-11-18 11:00:00')

[rockg]

And notice that if I remove the "0" in front of the offset, it works correctly as it goes into the dateutil parser (again the extra output is for debugging purposes).

>>> pd.to_datetime("2015-11-18 15:30:00+5:30")
ValueError: Error parsing datetime string "2015-11-18 15:30:00+5:30" at position 20
using parse_date 2015-11-18 15:30:00+5:30
Timestamp('2015-11-18 10:00:00')

[PShiw]

@rockg

Please note that "o" in time stamp was returned by Pandas only. For details refer below code.

pd.to_datetime(1419031147, utc=True, unit = 's').tz_convert('Asia/Kolkata')
Timestamp('2014-12-20 04:49:07+0530', tz='Asia/Kolkata')

[sinhrks]

Needs to look more, but the below line looks problematic. offset_minute should be added to total, not subtracted.

• https://github.com/pydata/pandas/blob/master/pandas/src/datetime/np_datetime_strings.c#L872

After the change, we get:

pd.to_datetime("2015-11-18 15:30:00+05:30").tz_localize('UTC').tz_convert('Asia/Kolkata')
# Timestamp('2015-11-18 15:30:00+0530', tz='Asia/Kolkata')

[rockg]

I agree that does look suspicious and that you should be adding and not subtracting. I guess we have no tests with a tzoffset that contains minutes?

[rockg]

Further confirmed with an even better example:

With subtraction:

In [2]: pd.to_datetime("2015-11-18 15:45:00+05:45")
tzinfo.utcoffset = 4:15:00
Out[2]: Timestamp('2015-11-18 11:30:00')

With addition:

In [2]: pd.to_datetime("2015-11-18 15:45:00+05:45")
tzinfo.utcoffset = 5:45:00
Out[2]: Timestamp('2015-11-18 10:00:00')

I'll open up a PR.