Timezone changes to local tz (when writing UTC) in TickStore

[pvk-1]

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Arctic Version

Arctic 1.80.0

Arctic Store

TickStore

Platform and version

Arctic 1.80.0, Windows 10, Mongo Server 4.4, python 3.7

Description of problem and/or code sample that reproduces the issue

In TickStore, when I run the example from the docs and write a dataframe with datetime index in UTC, reading back the data returns the df with an index in 'Europe/Berlin', my pc's local timezone.

Is this a bug? Is there a way to return the data in the UTC timestamp?

Code example:

import pandas as pd
from datetime import datetime as dt

from arctic import Arctic, TICK_STORE
from arctic.date._mktz import mktz


db = Arctic('localhost')
db.delete_library('temp')
db.initialize_library('temp', lib_type=TICK_STORE)
tickstore_lib = db['temp']

data = [{'A': 120, 'D': 1}, {'A': 122, 'B': 2.0}, {'A': 3, 'B': 3.0, 'D': 1}]
tick_index = [dt(2013, 6, 1, 12, 00, tzinfo=mktz('UTC')),
              dt(2013, 6, 1, 11, 00, tzinfo=mktz('UTC')),  # Out-of-order
              dt(2013, 6, 1, 13, 00, tzinfo=mktz('UTC'))]

data = pd.DataFrame(data, index=tick_index)

tickstore_lib._chunk_size = 3
tickstore_lib.write('SYM', data)
print(tickstore_lib.read('SYM', columns=None).index)

This outputs:

DatetimeIndex(['2013-06-01 13:00:00+02:00', '2013-06-01 14:00:00+02:00',
               '2013-06-01 15:00:00+02:00'],
              dtype='datetime64[ns, tzfile('Europe/Berlin')]', freq=None)

[shashank88]

Punting this to @jamesblackburn and/or @reasto

[chazkii]

Should be fixed as of https://github.com/man-group/arctic/commit/a1b8b31fec52a1f8deb52f699bd4f26c619cafd2