Develop Reference

Error in python while converting string to datetime with timezone

Code:
pd.to_datetime(dataset['startdate'] ,format="%Y-%m-%d %H:%M:%S%Z")
I got following error
ValueError: time data '2020-02-25 14:56:05+01' does not match format '%Y-%m-%d %H:%M:%S%Z' (match)
help much appreciate.

Your format has a %Z (uppercase) at the end, which according to docs timezone name (like GMT, PSD …). You probably want to use %z (lowercase) which is UTC offset (like ±HHMM[SS[.ffffff]]). However not sure if that would work +01, you might need +0100.

Times series data contains +01 and +02 as well due to daylight saving. That was causing an error. Should be using %z as well

Python timezone '%z' directive for datetime.strptime() not available

Using '%z' pattern of datetime.strptime()
I have a string text that represent a date and I'm perfectly able to parse it and transform it into a clean datetime object:
date = "[24/Aug/2014:17:57:26"
dt = datetime.strptime(date, "[%d/%b/%Y:%H:%M:%S")
Except that I can't catch the entire date string with the timezone using the %z pattern as specified here
date_tz = 24/Aug/2014:17:57:26 +0200
dt = datetime.strptime(date, "[%d/%b/%Y:%H:%M:%S %z]")
>>> ValueError: 'z' is a bad directive in format '[%d/%b/%Y:%H:%M:%S %z]'
Because as this bug report says
strftime() is implemented per platform
I precise that there is no such a problem with the naive tzinfo directive '%Z'
Workaround : Casting tzinfo string into tzinfo object
I can perfectly make the following workaround by transforming the GST time format string into a tzinfo object [as suggested here][4] using dateutil module
and then insert tzinfo into datetime object
Question: Make %z available for my plateform?
But as I will obviously need %z pattern for further project I would like to find a solution to avoid this workaround and using external module for this simple task.
Can you suggest me some reading on it? I supposed that newer version of python (I'm on 2.7) can handle it but I'd rather not changing my version now for this little but crucial detail.
[EDIT]
Well, seeing comments make me reformulated my question how to parse Email time zone indicator using strptime() without being aware of locale time?

strptime() is implemented in pure Python. Unlike strftime(); it [which directives are supported] doesn't depend on platform. %z is supported since Python 3.2:
>>> from datetime import datetime
>>> datetime.strptime('24/Aug/2014:17:57:26 +0200', '%d/%b/%Y:%H:%M:%S %z')
datetime.datetime(2014, 8, 24, 17, 57, 26, tzinfo=datetime.timezone(datetime.timedelta(0, 7200)))
how to parse Email time zone indicator using strptime() without being aware of locale time?
There is no concrete timezone implementation in Python 2.7. You could easily implement the UTC offset parsing, see How to parse dates with -0400 timezone string in python?

In continue to #j-f-sebastians 's answer, here is a fix for python 2.7
Instead of using:
datetime.strptime(t,'%Y-%m-%dT%H:%M %z')
use the timedelta to account for the timezone, like this:
from datetime import datetime,timedelta
def dt_parse(t):
ret = datetime.strptime(t[0:16],'%Y-%m-%dT%H:%M')
if t[17]=='+':
ret-=timedelta(hours=int(t[18:20]),minutes=int(t[20:]))
elif t[17]=='-':
ret+=timedelta(hours=int(t[18:20]),minutes=int(t[20:]))
return ret
print(dt_parse('2017-01-12T14:12 -0530'))

The Answer of Uri is great, saved my life, but when you have
USE_TZ = True you need to be careful with the time, for avoid the warning "RuntimeWarning: DateTimeField" is better if you add the utc to the return.
import pytz
from datetime import datetime, timedelta
def dt_parse(t):
ret = datetime.strptime(t[0:19],'%Y-%m-%dT%H:%M:%S')
if t[23]=='+':
ret-=timedelta(hours=int(t[24:26]), minutes=int(t[27:]))
elif t[23]=='-':
ret+=timedelta(hours=int(t[24:26]), minutes=int(t[27:]))
return ret.replace(tzinfo=pytz.UTC)

Python: strftime() UTC Offset Not working as Expected in Windows

Every time I use:
time.strftime("%z")
I get:
Eastern Daylight Time
However, I would like the UTC offset in the form +HHMM or -HHMM. I have even tried:
time.strftime("%Z")
Which still yields:
Eastern Daylight Time
I have read several other posts related to strftime() and %z always seems to return the UTC offset in the proper +HHMM or -HHMM format. How do I get strftime() to output in the +HHMM or -HHMM format for python 3.3?
Edit: I'm running Windows 7

In 2.x, if you look at the docs for time.strftime, they don't even mention %z. It's not guaranteed to exist at all, much less to be consistent across platforms. In fact, as footnote 1 implies, it's left up to the C strftime function. In 3.x, on the other hand, they do mention %z, and the footnote that explains that it doesn't work the way you'd expect is not easy to see; that's an open bug.
However, in 2.6+ (including all 3.x versions), datetime.strftime is guaranteed to support %z as "UTC offset in the form +HHMM or -HHMM (empty string if the the object is naive)." So, that makes for a pretty easy workaround: use datetime instead of time. Exactly how to change things depends on what exactly you're trying to do — using Python-dateutil tz then datetime.now(tz.tzlocal()).strftime('%z') is the way to get just the local timezone formatted as a GMT offset, but if you're trying to format a complete time the details will be a little different.
If you look at the source, time.strftime basically just checks the format string for valid-for-the-platform specifiers and calls the native strftime function, while datetime.strftime has a bunch of special handling for different specifiers, including %z; in particular, it will replace the %z with a formatted version of utcoffset before passing things on to strftime. The code has changed a few times since 2.7, and even been radically reorganized once, but the same difference is basically there even in the pre-3.5 trunk.

For a proper solution, see abarnert’s answer below.
You can use time.altzone which returns a negative offset in seconds. For example, I’m on CEST at the moment (UTC+2), so I get this:
>>> time.altzone
-7200
And to put it in your desired format:
>>> '{}{:0>2}{:0>2}'.format('-' if time.altzone > 0 else '+', abs(time.altzone) // 3600, abs(time.altzone // 60) % 60)
'+0200'
As abarnert mentioned in the comments, time.altzone gives the offset when DST is active while time.timezone does for when DST is not active. To figure out which to use, you can do what J.F. Sebastian suggested in his answer to a different question. So you can get the correct offset like this:
time.altzone if time.daylight and time.localtime().tm_isdst > 0 else time.timezone
As also suggested by him, you can use the following in Python 3 to get the desired format using datetime.timezone:
>>> datetime.now(timezone.utc).astimezone().strftime('%z')
'+0200'

Use time.timezone to get the time offset in seconds.
Format it using :
("-" if time.timezone > 0 else "+") + time.strftime("%H:%M", time.gmtime(abs(time.timezone)))
to convert the same to +/-HH:MM format.
BTW isn't this supposed to be a bug ? According to strftime docs.
Also I thought this SO answer might help you to convert from Zone offset string to HH:MM format. But since "%z" is not working as expected, I feel its moot.
NOTE: The time.timezone is immune to Daylight savings.

It will come as no surprise that this bug persists in, what is the latest Windows version available currently, Win 10 Version 1703 (Creators). However, time marches on and there is a lovely date-and-time library called pendulum that does what the question asks for. Sébastien Eustace (principal author of the product?) has shown me this.
>>> pendulum.now().strftime('%z')
'-0400'
pendulum assumes UTC/GMT unless told otherwise, and keeps timezone with the date-time object. There are many other possibilities, amongst them these:
>>> pendulum.now(tz='Europe/Paris').strftime('%z')
'+0200'
>>> pendulum.create(year=2016, month=11, day=5, hour=16, minute=23, tz='America/Winnipeg').strftime('%z')
'-0500'
>>> pendulum.now(tz='America/Winnipeg').strftime('%z')
'-0500'

Using python datetime.datetime.strptime on windows with BST timezone

I need to parse many different dates in many different formats. I am having trouble with the following and wondered if anyopne could explain why;
The following works on a linux system:
from datetime import datetime
datetime.strptime('Tue 23 Aug 2011 09:00:07 PM BST','%a %d %b %Y %H:%M:%S %p %Z')
But running under windows it raises
ValueError: time data does not match format
However, if I try GMT not BST on windows, it works fine;
from datetime import datetime
datetime.strptime('Tue 23 Aug 2011 09:00:07 PM GMT','%a %d %b %Y %H:%M:%S %p %Z')
Is there a reason python does not understand the BST timezone under windows, but it works fine under Linux?
thanks,
Matt.

In my opinion, parsing a three-letter time zone code like this is not a good practice (unless of course you have no choice). For example, "EST" is commonly used in the USA for UTC-4/5 and is also commonly used in Australia. So any support for "EST" must therefore be dependent on locale. It would not surprise me if "BST" was similarly ambiguous.
I highly recommend using the pytz module in which British civil time is given the string identifier Europe/London and UTC is called Etc/UTC. The pytz API will give consistent results regardless of the locale of the user or system running the application.
If you are working on a UI that must be tied to locale, or parsing inputs with formats you cannot change, then consider using a dictionary of abbreviations to pytz timezone objects. For example: {'BST': 'Europe/London'}. Then your application can work with UTC dates and times uniformly, which will greatly reduce the possibility of errors.

How do I find difference between times in different timezones in Python?

I am trying to calculate difference(in seconds) between two date/times formatted as following:
2010-05-11 17:07:33 UTC
2010-05-11 17:07:33 EDT
time1 = '2010-05-11 17:07:33 UTC'
time2 = '2010-05-11 17:07:33 EDT'
delta = time.mktime(time.strptime(time1,"%Y-%m-%d %H:%M:%S %Z"))-\
time.mktime(time.strptime(time2, "%Y-%m-%d %H:%M:%S %Z"))
The problem I got is EDT is not recognized, the specific error is
ValueError: time data '2010-05-11 17:07:33 EDT' does not match format '%Y-%m-%d %H:%M:%S %Z'

Check out the pytz world timezone definitions library.
This library allows accurate and cross platform timezone calculations using Python 2.3 or higher. It also solves the issue of ambiguous times at the end of daylight savings, which you can read more about in the Python Library Reference (datetime.tzinfo).
It takes advantage of the tz database, which should include EDT, and allow you to perform the calculations you need to (and probably more reliably & accurately than your current implementation).

In addition to pytz, check out python-dateutil. The relativedelta functionality is outstanding.
Here's a sample of using them together:
from datetime import datetime
from dateutil.relativedelta import *
import pytz
if __name__ == '__main__':
date_one = datetime.now(pytz.timezone('US/Eastern'))
date_two = datetime.now(pytz.timezone('US/Mountain'))
rdelta = relativedelta(date_one, date_two)
print(rdelta)

From docs for strptime
Support for the %Z directive is based
on the values contained in tzname and
whether daylight is true. Because of
this, it is platform-specific except
for recognizing UTC and GMT which are
always known (and are considered to be
non-daylight savings timezones).