python parse datetime from string with timezone

How to convert a timezone aware string to datetime in Python without dateutil?

stackoverflow.com › questions › 13182075 › how-to-convert-a-timezone-aware-string-to-datetime-in-python-without-dateutil

As of Python 3.7, datetime.datetime.fromisoformat() can handle your format:

>>> import datetime
>>> datetime.datetime.fromisoformat('2012-11-01T04:16:13-04:00')
datetime.datetime(2012, 11, 1, 4, 16, 13, tzinfo=datetime.timezone(datetime.timedelta(days=-1, seconds=72000)))

In older Python versions you can't, not without a whole lot of painstaking manual timezone defining.

Python versions before version 3.9 do not include a timezone database, because it would be outdated too quickly. Instead, for those versions Python relied on external libraries, which can have a far faster release cycle, to provide properly configured timezones for you.

As a side-effect, this means that timezone parsing also needs to be an external library. If dateutil is too heavy-weight for you, use iso8601 instead, it'll parse your specific format just fine:

>>> import iso8601
>>> iso8601.parse_date('2012-11-01T04:16:13-04:00')
datetime.datetime(2012, 11, 1, 4, 16, 13, tzinfo=<FixedOffset '-04:00'>)

iso8601 is a whopping 4KB small. Compare that tot python-dateutil's 148KB.

As of Python 3.2 Python can handle simple offset-based timezones, and %z will parse -hhmm and +hhmm timezone offsets in a timestamp. That means that for a ISO 8601 timestamp you'd have to remove the : in the timezone:

>>> from datetime import datetime
>>> iso_ts = '2012-11-01T04:16:13-04:00'
>>> datetime.strptime(''.join(iso_ts.rsplit(':', 1)), '%Y-%m-%dT%H:%M:%S%z')
datetime.datetime(2012, 11, 1, 4, 16, 13, tzinfo=datetime.timezone(datetime.timedelta(-1, 72000)))

The lack of proper ISO 8601 parsing was being tracked in Python issue 15873 (since migrated to GitHub issue #60077).

Answer from Martijn Pieters on Stack Overflow

Stack Overflow

stackoverflow.com › questions › 13182075 › how-to-convert-a-timezone-aware-string-to-datetime-in-python-without-dateutil

How to convert a timezone aware string to datetime in Python without dateutil? - Stack Overflow

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reddit.com › r/learnpython › parse date string: best way to parse string containing utc

r/learnpython on Reddit: Parse date string: Best way to parse string containing UTC

January 19, 2022 -

Hi.

Consider this text string: 2021-01-01 01:01:00 UTC.

What's the best way of parsing this into a date object in Python 3? I could remove the "UTC" from the text, and then use something like datetime.strptime(date_string, format), but isn't there an easier way, like doesn't Python already have support for parseing strings like these?

Top answer

1 of 6

135

You can use the parse function from dateutil:

>>> from dateutil.parser import parse
>>> d = parse('2009/05/13 19:19:30 -0400')
>>> d
datetime.datetime(2009, 5, 13, 19, 19, 30, tzinfo=tzoffset(None, -14400))

This way you obtain a datetime object you can then use.

As answered, dateutil2.0 is written for Python 3.0 and does not work with Python 2.x. For Python 2.x dateutil1.5 needs to be used.

2 of 6

%z is supported in Python 3.2+:

>>> from datetime import datetime
>>> datetime.strptime('2009/05/13 19:19:30 -0400', '%Y/%m/%d %H:%M:%S %z')
datetime.datetime(2009, 5, 13, 19, 19, 30,
                  tzinfo=datetime.timezone(datetime.timedelta(-1, 72000)))

On earlier versions:

from datetime import datetime

date_str = '2009/05/13 19:19:30 -0400'
naive_date_str, _, offset_str = date_str.rpartition(' ')
naive_dt = datetime.strptime(naive_date_str, '%Y/%m/%d %H:%M:%S')
offset = int(offset_str[-4:-2])*60 + int(offset_str[-2:])
if offset_str[0] == "-":
   offset = -offset
dt = naive_dt.replace(tzinfo=FixedOffset(offset))
print(repr(dt))
# -> datetime.datetime(2009, 5, 13, 19, 19, 30, tzinfo=FixedOffset(-240))
print(dt)
# -> 2009-05-13 19:19:30-04:00

where FixedOffset is a class based on the code example from the docs:

from datetime import timedelta, tzinfo

class FixedOffset(tzinfo):
    """Fixed offset in minutes: `time = utc_time + utc_offset`."""
    def __init__(self, offset):
        self.__offset = timedelta(minutes=offset)
        hours, minutes = divmod(offset, 60)
        #NOTE: the last part is to remind about deprecated POSIX GMT+h timezones
        #  that have the opposite sign in the name;
        #  the corresponding numeric value is not used e.g., no minutes
        self.__name = '<%+03d%02d>%+d' % (hours, minutes, -hours)
    def utcoffset(self, dt=None):
        return self.__offset
    def tzname(self, dt=None):
        return self.__name
    def dst(self, dt=None):
        return timedelta(0)
    def __repr__(self):
        return 'FixedOffset(%d)' % (self.utcoffset().total_seconds() / 60)

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Readthedocs

dateparser.readthedocs.io › en › latest

dateparser – python parser for human readable dates — DateParser 1.3.0 documentation

>>> parse('18-12-15 06:00', settings={'DATE_ORDER': 'DMY'}) datetime.datetime(2015, 12, 18, 6, 0) ... By default, dateparser returns tzaware datetime if timezone is present in date string.

dateutil

dateutil.readthedocs.io › en › stable › parser.html

parser — dateutil 3.9.0 documentation - Read the Docs

ignoretz – If set True, time zones in parsed strings are ignored and a naive datetime object is returned. ... Additional time zone names / aliases which may be present in the string. This argument maps time zone names (and optionally offsets from those time zones) to time zones. This parameter can be a dictionary with timezone aliases mapping time zone names to time zones or a function taking two parameters (tzname and tzoffset) and returning a time zone.

Python Guides

pythonguides.com › convert-a-string-to-datetime-in-python

Convert Python String to Datetime with Timezone

September 23, 2025 - from dateutil import parser import pytz # Example timestamp string with timezone info timestamp_str = "September 23, 2025 2:30 PM EST" # Step 1: Parse string directly dt_parsed = parser.parse(timestamp_str) # Step 2: Convert to another timezone (e.g., Pacific Time) pacific = pytz.timezone("America/Los_Angeles") dt_pacific = dt_parsed.astimezone(pacific) print("Parsed datetime:", dt_parsed) print("Converted to Pacific Time:", dt_pacific) You can see the output in the screenshot below. This method is my favorite when dealing with user input or messy log files. I don’t need to specify the forma

Iditect

iditect.com › faq › python › how-to-preserve-timezone-when-parsing-datetime-strings-with-strptime-in-python.html

How to preserve timezone when parsing date/time strings with strptime() in python?

This code snippet demonstrates parsing a date/time string with timezone information using %z format specifier in strptime() function, preserving the timezone in the resulting datetime object. ... Description: Users may specifically look for ways to ensure that the timezone offset is preserved ...

Stack Abuse

stackabuse.com › converting-strings-to-datetime-in-python

Converting Strings to datetime in Python

June 21, 2023 - As you can see, all of the date formats were successfully parsed! If we don't provide the timezone info then, it automatically converts it to UTC. So, it is important to note that we must provide the to_timezone and naive parameters if the time is not in UTC. Arrow is another library for dealing with datetime in Python. And like before with maya, it also figures out the datetime format automatically. Once interpreted, it returns a Python datetime object from the arrow object. To easily convert a string ...

PYnative

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Python String to DateTime using Strptime() [5 Ways] – PYnative

December 5, 2021 - from datetime import datetime # ... as timedelta (+/-) or with the timezone names to the datetime object using the %z and %Z format directives....

Inventive HQ

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Python Datetime Format: strftime, strptime & Date Conversion Examples

November 6, 2025 - from datetime import datetime # ISO 8601 format iso_string = "2023-07-11T14:30:00" iso_datetime = datetime.fromisoformat(iso_string) # With timezone info iso_with_tz = "2023-07-11T14:30:00-04:00" datetime_with_tz = datetime.fromisoformat(iso_with_tz) Copy · When working with datetime parsing, always handle potential errors:

alpharithms

alpharithms.com › home › tutorials › converting between strings and datetime objects in python

Converting Between Strings and Datetime Objects in Python - αlphαrithms

June 17, 2022 - The above references and general use of the strptime method provides the groundwork for converting strings to datetime objects in Python. The essential steps of this process are as follows: ... Below is a slightly more complex example in which ...

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pandas.pydata.org › docs › reference › api › pandas.to_datetime.html

pandas.to_datetime — pandas 3.0.1 documentation - PyData |

See also: pandas general documentation about timezone conversion and localization. ... The strftime to parse time, e.g. "%d/%m/%Y". See strftime documentation for more information on choices, though note that "%f" will parse all the way up to nanoseconds. You can also pass: “ISO8601”, to parse any ISO8601 time string (not necessarily in exactly the same format);

Abdul Wahab Junaid

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Parsing a string into a timezone aware datetime object in python | Abdul Wahab Junaid

August 13, 2023 - Parse the String with Time Zone Information: Use the datetime.strptime() function to parse the string into a datetime object and then use pytz.timezone() to specify the desired time zone.

Medium

medium.com › @generativeai.saif › how-to-convert-a-string-to-a-date-in-python-complete-guide-for-2025-bd5ece07c57c

How to Convert a String to a Date in Python: Complete Guide for 2025 | by Saif Ali | Medium

April 6, 2025 - For robust timezone handling, you’ll typically use the pytz library: from datetime import datetime import pytz # Parse a string with timezone information timezone_string = "2025-04-02 14:30:45+05:30" timezone_aware = datetime.strptime(tim...

Cheat Sheets

cheat.readthedocs.io › en › latest › python › timezones.html

Timezones in Python — Dan's Cheat Sheets 1 documentation

So here’s one of the problems - we don’t KNOW what timezone this date/time is from, we only know the current offset from UTC. So, the best we can do is to figure out the corresponding time in UTC, then create an aware object in UTC. We know this time is 240 minutes less than the corresponding UTC time, so: >>> import time >>> time_seconds = time.mktime(dt.timetuple()) >>> time_seconds -= 60*minutes >>> utc_time = datetime.datetime.fromtimestamp(time_seconds, pytz.utc) >>> utc_time datetime.datetime(2012, 7, 3, 22, 11, 3, tzinfo=<UTC>)

Medium

medium.com › @eleroy › 10-things-you-need-to-know-about-date-and-time-in-python-with-datetime-pytz-dateutil-timedelta-309bfbafb3f7

10 things you need to know about Date and Time in Python with datetime, pytz, dateutil & timedelta | by Emmanuel | Medium

October 8, 2023 - A time offset is the timezone offset that needs to be added to UTC time to represent local time. ISO-8601 is a standard to represent date strings, including time offsets. It’s really able to represent date string in many different format, but the most commonly used format in computing is: ... to parse an ISO-8601 string in python >3.2, you can use the same function as shown in 1. but if you’re using python 2.7, you’ll need dateutil.parser: import datetime import dateutil.parserformat = '%Y-%m-%dT%H:%M:%S%z' datestring = '2016-09-20T16:43:45-07:00' d = dateutil.parser.parse(datestring) # python 2.7 d = datetime.datetime.strptime(datestring, format) #3.2+