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I have a CSV dumpfile from a Blackberry IPD backup, created using IPDDump.
The date/time strings in here look something like this
(where EST is an Australian time-zone):
Tue Jun 22 07:46:22 EST 2010
I need to be able to parse this date in Python. At first, I tried to use the strptime() function from datettime.
>>> datetime.datetime.strptime('Tue Jun 22 12:10:20 2010 EST', '%a %b %d %H:%M:%S %Y %Z')
However, for some reason, the datetime object that comes back doesn't seem to have any tzinfo associated with it.
I did read on this page that apparently datetime.strptime silently discards tzinfo, however, I checked the documentation, and I can't find anything to that effect documented here.
Is there any way to get strptime() to play nicely with timezones?
I recommend using python-dateutil. Its parser has been able to parse every date format I've thrown at it so far.
>>> from dateutil import parser
>>> parser.parse("Tue Jun 22 07:46:22 EST 2010")
datetime.datetime(2010, 6, 22, 7, 46, 22, tzinfo=tzlocal())
>>> parser.parse("Fri, 11 Nov 2011 03:18:09 -0400")
datetime.datetime(2011, 11, 11, 3, 18, 9, tzinfo=tzoffset(None, -14400))
>>> parser.parse("Sun")
datetime.datetime(2011, 12, 18, 0, 0)
>>> parser.parse("10-11-08")
datetime.datetime(2008, 10, 11, 0, 0)
and so on. No dealing with strptime() format nonsense... just throw a date at it and it Does The Right Thing.
The datetime module documentation says:
Return a datetime corresponding to date_string, parsed according to format. This is equivalent to datetime(*(time.strptime(date_string, format)[0:6])).
See that [0:6]? That gets you (year, month, day, hour, minute, second). Nothing else. No mention of timezones.
Interestingly, [Win XP SP2, Python 2.6, 2.7] passing your example to time.strptime doesn't work but if you strip off the " %Z" and the " EST" it does work. Also using "UTC" or "GMT" instead of "EST" works. "PST" and "MEZ" don't work. Puzzling.
It's worth noting this has been updated as of version 3.2 and the same documentation now also states the following:
When the %z directive is provided to the strptime() method, an aware datetime object will be produced. The tzinfo of the result will be set to a timezone instance.
Note that this doesn't work with %Z, so the case is important. See the following example:
In [1]: from datetime import datetime
In [2]: start_time = datetime.strptime('2018-04-18-17-04-30-AEST','%Y-%m-%d-%H-%M-%S-%Z')
In [3]: print("TZ NAME: {tz}".format(tz=start_time.tzname()))
TZ NAME: None
In [4]: start_time = datetime.strptime('2018-04-18-17-04-30-+1000','%Y-%m-%d-%H-%M-%S-%z')
In [5]: print("TZ NAME: {tz}".format(tz=start_time.tzname()))
TZ NAME: UTC+10:00
Since strptime returns a datetime object which has tzinfo attribute, We can simply replace it with desired timezone.
>>> import datetime
>>> date_time_str = '2018-06-29 08:15:27.243860'
>>> date_time_obj = datetime.datetime.strptime(date_time_str, '%Y-%m-%d %H:%M:%S.%f').replace(tzinfo=datetime.timezone.utc)
>>> date_time_obj.tzname()
'UTC'
Your time string is similar to the time format in rfc 2822 (date format in email, http headers). You could parse it using only stdlib:
>>> from email.utils import parsedate_tz
>>> parsedate_tz('Tue Jun 22 07:46:22 EST 2010')
(2010, 6, 22, 7, 46, 22, 0, 1, -1, -18000)
See solutions that yield timezone-aware datetime objects for various Python versions: parsing date with timezone from an email.
In this format, EST is semantically equivalent to -0500. Though, in general, a timezone abbreviation is not enough, to identify a timezone uniquely.
Ran into this exact problem.
What I ended up doing:
# starting with date string
sdt = "20190901"
std_format = '%Y%m%d'
# create naive datetime object
from datetime import datetime
dt = datetime.strptime(sdt, sdt_format)
# extract the relevant date time items
dt_formatters = ['%Y','%m','%d']
dt_vals = tuple(map(lambda formatter: int(datetime.strftime(dt,formatter)), dt_formatters))
# set timezone
import pendulum
tz = pendulum.timezone('utc')
dt_tz = datetime(*dt_vals,tzinfo=tz)
How do I convert a time to another timezone in Python?
I have found that the best approach is to convert the "moment" of interest to a utc-timezone-aware datetime object (in python, the timezone component is not required for datetime objects).
Then you can use astimezone to convert to the timezone of interest (reference).
from datetime import datetime
import pytz
utcmoment_naive = datetime.utcnow()
utcmoment = utcmoment_naive.replace(tzinfo=pytz.utc)
# print "utcmoment_naive: {0}".format(utcmoment_naive) # python 2
print("utcmoment_naive: {0}".format(utcmoment_naive))
print("utcmoment: {0}".format(utcmoment))
localFormat = "%Y-%m-%d %H:%M:%S"
timezones = ['America/Los_Angeles', 'Europe/Madrid', 'America/Puerto_Rico']
for tz in timezones:
localDatetime = utcmoment.astimezone(pytz.timezone(tz))
print(localDatetime.strftime(localFormat))
# utcmoment_naive: 2017-05-11 17:43:30.802644
# utcmoment: 2017-05-11 17:43:30.802644+00:00
# 2017-05-11 10:43:30
# 2017-05-11 19:43:30
# 2017-05-11 13:43:30
So, with the moment of interest in the local timezone (a time that exists), you convert it to utc like this (reference).
localmoment_naive = datetime.strptime('2013-09-06 14:05:10', localFormat)
localtimezone = pytz.timezone('Australia/Adelaide')
try:
localmoment = localtimezone.localize(localmoment_naive, is_dst=None)
print("Time exists")
utcmoment = localmoment.astimezone(pytz.utc)
except pytz.exceptions.NonExistentTimeError as e:
print("NonExistentTimeError")
Using pytz
from datetime import datetime
from pytz import timezone
fmt = "%Y-%m-%d %H:%M:%S %Z%z"
timezonelist = ['UTC','US/Pacific','Europe/Berlin']
for zone in timezonelist:
now_time = datetime.now(timezone(zone))
print now_time.strftime(fmt)
import datetime
import pytz
def convert_datetime_timezone(dt, tz1, tz2):
tz1 = pytz.timezone(tz1)
tz2 = pytz.timezone(tz2)
dt = datetime.datetime.strptime(dt,"%Y-%m-%d %H:%M:%S")
dt = tz1.localize(dt)
dt = dt.astimezone(tz2)
dt = dt.strftime("%Y-%m-%d %H:%M:%S")
return dt
-
dt: date time string
tz1: initial time zone
tz2: target time zone
-
> convert_datetime_timezone("2017-05-13 14:56:32", "Europe/Berlin", "PST8PDT")
'2017-05-13 05:56:32'
> convert_datetime_timezone("2017-05-13 14:56:32", "Europe/Berlin", "UTC")
'2017-05-13 12:56:32'
-
> pytz.all_timezones[0:10]
['Africa/Abidjan',
'Africa/Accra',
'Africa/Addis_Ababa',
'Africa/Algiers',
'Africa/Asmara',
'Africa/Asmera',
'Africa/Bamako',
'Africa/Bangui',
'Africa/Banjul',
'Africa/Bissau']
Python 3.9 adds the zoneinfo module so now only the the standard library is needed!
>>> from zoneinfo import ZoneInfo
>>> from datetime import datetime
>>> d = datetime(2020, 10, 31, 12, tzinfo=ZoneInfo('America/Los_Angeles'))
>>> d.astimezone(ZoneInfo('Europe/Berlin')) # 12:00 in Cali will be 20:00 in Berlin
datetime.datetime(2020, 10, 31, 20, 0, tzinfo=zoneinfo.ZoneInfo(key='Europe/Berlin'))
Wikipedia list of available time zones
Some functions such as now() and utcnow() return timezone-unaware datetimes, meaning they contain no timezone information. I recommend only requesting timezone-aware values from them using the keyword tz=ZoneInfo('localtime').
If astimezone gets a timezone-unaware input, it will assume it is local time, which can lead to errors:
>>> datetime.utcnow() # UTC -- NOT timezone-aware!!
datetime.datetime(2020, 6, 1, 22, 39, 57, 376479)
>>> datetime.now() # Local time -- NOT timezone-aware!!
datetime.datetime(2020, 6, 2, 0, 39, 57, 376675)
>>> datetime.now(tz=ZoneInfo('localtime')) # timezone-aware
datetime.datetime(2020, 6, 2, 0, 39, 57, 376806, tzinfo=zoneinfo.ZoneInfo(key='localtime'))
>>> datetime.now(tz=ZoneInfo('Europe/Berlin')) # timezone-aware
datetime.datetime(2020, 6, 2, 0, 39, 57, 376937, tzinfo=zoneinfo.ZoneInfo(key='Europe/Berlin'))
>>> datetime.utcnow().astimezone(ZoneInfo('Europe/Berlin')) # WRONG!!
datetime.datetime(2020, 6, 1, 22, 39, 57, 377562, tzinfo=zoneinfo.ZoneInfo(key='Europe/Berlin'))
Windows has no system time zone database, so here an extra package is needed:
pip install tzdata
There is a backport to allow use in Python 3.6 to 3.8:
sudo pip install backports.zoneinfo
Then:
from backports.zoneinfo import ZoneInfo
Time conversion
To convert a time in one timezone to another timezone in Python, you could use datetime.astimezone():
so, below code is to convert the local time to other time zone.
datetime.datetime.today() - return current the local time
datetime.astimezone() - convert the time zone, but we have to pass the time zone.
pytz.timezone('Asia/Kolkata') -passing the time zone to pytz module
Strftime - Convert Datetime to string
# Time conversion from local time
import datetime
import pytz
dt_today = datetime.datetime.today() # Local time
dt_India = dt_today.astimezone(pytz.timezone('Asia/Kolkata'))
dt_London = dt_today.astimezone(pytz.timezone('Europe/London'))
India = (dt_India.strftime('%m/%d/%Y %H:%M'))
London = (dt_London.strftime('%m/%d/%Y %H:%M'))
print("Indian standard time: "+India+" IST")
print("British Summer Time: "+London+" BST")
List all the time zones
import pytz
for tz in pytz.all_timezones:
print(tz)
To convert a time in one timezone to another timezone in Python, you could use datetime.astimezone():
time_in_new_timezone = time_in_old_timezone.astimezone(new_timezone)
Given aware_dt (a datetime object in some timezone), to convert it to other timezones and to print the times in a given time format:
#!/usr/bin/env python3
import pytz # $ pip install pytz
time_format = "%Y-%m-%d %H:%M:%S%z"
tzids = ['Asia/Shanghai', 'Europe/London', 'America/New_York']
for tz in map(pytz.timezone, tzids):
time_in_tz = aware_dt.astimezone(tz)
print(f"{time_in_tz:{time_format}}")
If f"" syntax is unavailable, you could replace it with "".format(**vars())
where you could set aware_dt from the current time in the local timezone:
from datetime import datetime
import tzlocal # $ pip install tzlocal
local_timezone = tzlocal.get_localzone()
aware_dt = datetime.now(local_timezone) # the current time
Or from the input time string in the local timezone:
naive_dt = datetime.strptime(time_string, time_format)
aware_dt = local_timezone.localize(naive_dt, is_dst=None)
where time_string could look like: '2016-11-19 02:21:42'. It corresponds to time_format = '%Y-%m-%d %H:%M:%S'.
is_dst=None forces an exception if the input time string corresponds to a non-existing or ambiguous local time such as during a DST transition. You could also pass is_dst=False, is_dst=True. See links with more details at Python: How do you convert datetime/timestamp from one timezone to another timezone?
For Python timezone conversions, I use the handy table from the PyCon 2012 presentation by Taavi Burns.
Please note: The first part of this answer is or version 1.x of pendulum. See below for a version 2.x answer.
I hope I'm not too late!
The pendulum library excels at this and other date-time calculations.
>>> import pendulum
>>> some_time_zones = ['Europe/Paris', 'Europe/Moscow', 'America/Toronto', 'UTC', 'Canada/Pacific', 'Asia/Macao']
>>> heres_a_time = '1996-03-25 12:03 -0400'
>>> pendulum_time = pendulum.datetime.strptime(heres_a_time, '%Y-%m-%d %H:%M %z')
>>> for tz in some_time_zones:
... tz, pendulum_time.astimezone(tz)
...
('Europe/Paris', <Pendulum [1996-03-25T17:03:00+01:00]>)
('Europe/Moscow', <Pendulum [1996-03-25T19:03:00+03:00]>)
('America/Toronto', <Pendulum [1996-03-25T11:03:00-05:00]>)
('UTC', <Pendulum [1996-03-25T16:03:00+00:00]>)
('Canada/Pacific', <Pendulum [1996-03-25T08:03:00-08:00]>)
('Asia/Macao', <Pendulum [1996-03-26T00:03:00+08:00]>)
Answer lists the names of the time zones that may be used with pendulum. (They're the same as for pytz.)
For version 2:
some_time_zones is a list of the names of the time zones that might be used in a program
heres_a_time is a sample time, complete with a time zone in the form '-0400'
I begin by converting the time to a pendulum time for subsequent processing
now I can show what this time is in each of the time zones in show_time_zones
...
>>> import pendulum
>>> some_time_zones = ['Europe/Paris', 'Europe/Moscow', 'America/Toronto', 'UTC', 'Canada/Pacific', 'Asia/Macao']
>>> heres_a_time = '1996-03-25 12:03 -0400'
>>> pendulum_time = pendulum.from_format('1996-03-25 12:03 -0400', 'YYYY-MM-DD hh:mm ZZ')
>>> for tz in some_time_zones:
... tz, pendulum_time.in_tz(tz)
...
('Europe/Paris', DateTime(1996, 3, 25, 17, 3, 0, tzinfo=Timezone('Europe/Paris')))
('Europe/Moscow', DateTime(1996, 3, 25, 19, 3, 0, tzinfo=Timezone('Europe/Moscow')))
('America/Toronto', DateTime(1996, 3, 25, 11, 3, 0, tzinfo=Timezone('America/Toronto')))
('UTC', DateTime(1996, 3, 25, 16, 3, 0, tzinfo=Timezone('UTC')))
('Canada/Pacific', DateTime(1996, 3, 25, 8, 3, 0, tzinfo=Timezone('Canada/Pacific')))
('Asia/Macao', DateTime(1996, 3, 26, 0, 3, 0, tzinfo=Timezone('Asia/Macao')))
For Python 3.2+ simple-date is a wrapper around pytz that tries to simplify things.
If you have a time then
SimpleDate(time).convert(tz="...")
may do what you want. But timezones are quite complex things, so it can get significantly more complicated - see the the docs.
# Program
import time
import os
os.environ['TZ'] = 'US/Eastern'
time.tzset()
print('US/Eastern in string form:',time.asctime())
os.environ['TZ'] = 'Australia/Melbourne'
time.tzset()
print('Australia/Melbourne in string form:',time.asctime())
os.environ['TZ'] = 'Asia/Kolkata'
time.tzset()
print('Asia/Kolkata in string form:',time.asctime())
The time module can be initialized using seconds since epoch:
>>> import time
>>> t1=time.gmtime(1284286794)
>>> t1
time.struct_time(tm_year=2010, tm_mon=9, tm_mday=12, tm_hour=10, tm_min=19,
tm_sec=54, tm_wday=6, tm_yday=255, tm_isdst=0)
Is there an elegant way to initialize a datetime.datetime object in the same way?
datetime.datetime.fromtimestamp will do, if you know the time zone, you could produce the same output as with time.gmtime
>>> datetime.datetime.fromtimestamp(1284286794)
datetime.datetime(2010, 9, 12, 11, 19, 54)
or
>>> datetime.datetime.utcfromtimestamp(1284286794)
datetime.datetime(2010, 9, 12, 10, 19, 54)
Seconds since epoch to datetime to strftime:
>>> ts_epoch = 1362301382
>>> ts = datetime.datetime.fromtimestamp(ts_epoch).strftime('%Y-%m-%d %H:%M:%S')
>>> ts
'2013-03-03 01:03:02'
From the docs, the recommended way of getting a timezone aware datetime object from seconds since epoch is:
Python 3:
from datetime import datetime, timezone
datetime.fromtimestamp(timestamp, timezone.utc)
Python 2, using pytz:
from datetime import datetime
import pytz
datetime.fromtimestamp(timestamp, pytz.utc)
Note that datetime.datetime.fromtimestamp(timestamp) and .utcfromtimestamp(timestamp) fail on windows for dates before Jan. 1, 1970 while negative unix timestamps seem to work on unix-based platforms. The docs say this:
"This may raise ValueError, if the timestamp is out of the range of
values supported by the platform C gmtime() function. It’s common for
this to be restricted to years in 1970 through 2038"
See also Issue1646728
For those that want it ISO 8601 compliant, since the other solutions do not have the T separator nor the time offset (except Meistro's answer):
from datetime import datetime, timezone
result = datetime.fromtimestamp(1463288494, timezone.utc).isoformat('T', 'microseconds')
print(result) # 2016-05-15T05:01:34.000000+00:00
Note, I use fromtimestamp because if I used utcfromtimestamp I would need to chain on .astimezone(...) anyway to get the offset.
If you don't want to go all the way to microseconds you can choose a different unit with the
isoformat() method.
I want to compare UTC timestamps from a log file with local timestamps. When creating the local datetime object, I use something like:
>>> local_time=datetime.datetime(2010, 4, 27, 12, 0, 0, 0,
tzinfo=pytz.timezone('Israel'))
I want to find an automatic tool that would replace thetzinfo=pytz.timezone('Israel') with the current local time zone.
Any ideas?
In Python 3.x, local timezone can be figured out like this:
>>> import datetime
>>> print(datetime.datetime.now(datetime.timezone.utc).astimezone().tzinfo)
AEST
It's a tricky use of datetime's code .
For python < 3.6, you'll need
>>> import datetime
>>> print(datetime.datetime.now(datetime.timezone(datetime.timedelta(0))).astimezone().tzinfo)
AEST
Try dateutil, which has a tzlocal type that does what you need.
to compare UTC timestamps from a log file with local timestamps.
It is hard to find out Olson TZ name for a local timezone in a portable manner. Fortunately, you don't need it to perform the comparison.
tzlocal module returns a pytz timezone corresponding to the local timezone:
from datetime import datetime
import pytz # $ pip install pytz
from tzlocal import get_localzone # $ pip install tzlocal
tz = get_localzone()
local_dt = tz.localize(datetime(2010, 4, 27, 12, 0, 0, 0), is_dst=None)
utc_dt = local_dt.astimezone(pytz.utc) #NOTE: utc.normalize() is unnecessary here
Unlike other solutions presented so far the above code avoids the following issues:
local time can be ambiguous i.e., a precise comparison might be impossible for some local times
utc offset can be different for the same local timezone name for dates in the past. Some libraries that support timezone-aware datetime objects (e.g., dateutil) fail to take that into account
Note: to get timezone-aware datetime object from a naive datetime object, you should use*:
local_dt = tz.localize(datetime(2010, 4, 27, 12, 0, 0, 0), is_dst=None)
instead of:
#XXX fails for some timezones
local_dt = datetime(2010, 4, 27, 12, 0, 0, 0, tzinfo=tz)
*is_dst=None forces an exception if given local time is ambiguous or non-existent.
If you are certain that all local timestamps use the same (current) utc offset for the local timezone then you could perform the comparison using only stdlib:
# convert a naive datetime object that represents time in local timezone to epoch time
timestamp1 = (datetime(2010, 4, 27, 12, 0, 0, 0) - datetime.fromtimestamp(0)).total_seconds()
# convert a naive datetime object that represents time in UTC to epoch time
timestamp2 = (datetime(2010, 4, 27, 9, 0) - datetime.utcfromtimestamp(0)).total_seconds()
timestamp1 and timestamp2 can be compared directly.
Note:
timestamp1 formula works only if the UTC offset at epoch (datetime.fromtimestamp(0)) is the same as now
fromtimestamp() creates a naive datetime object in the current local timezone
utcfromtimestamp() creates a naive datetime object in UTC.
I was asking the same to myself, and I found the answer in 1:
Take a look at section 8.1.7: the format "%z" (lowercase, the Z uppercase returns also the time zone, but not in the 4-digit format, but in the form of timezone abbreviations, like in [3]) of strftime returns the form "+/- 4DIGIT" that is standard in email headers (see section 3.3 of RFC 2822, see [2], which obsoletes the other ways of specifying the timezone for email headers).
So, if you want your timezone in this format, use:
time.strftime("%z")
[1] http://docs.python.org/2/library/datetime.html
[2] https://www.rfc-editor.org/rfc/rfc2822#section-3.3
[3] Timezone abbreviations: http://en.wikipedia.org/wiki/List_of_time_zone_abbreviations , only for reference.
The following appears to work for 3.7+, using standard libs:
from datetime import timedelta
from datetime import timezone
import time
def currenttz():
if time.daylight:
return timezone(timedelta(seconds=-time.altzone),time.tzname[1])
else:
return timezone(timedelta(seconds=-time.timezone),time.tzname[0])
First get pytz and tzlocal modules
pip install pytz tzlocal
then
from tzlocal import get_localzone
local = get_localzone()
then you can do things like
from datetime import datetime
print(datetime.now(local))
Here's a way to get the local timezone using only the standard library, (only works in a *nix environment):
>>> '/'.join(os.path.realpath('/etc/localtime').split('/')[-2:])
'Australia/Sydney'
You can use this to create a pytz timezone:
>>> import pytz
>>> my_tz_name = '/'.join(os.path.realpath('/etc/localtime').split('/')[-2:])
>>> my_tz = pytz.timezone(my_tz_name)
>>> my_tz
<DstTzInfo 'Australia/Sydney' LMT+10:05:00 STD>
...which you can then apply to a datetime:
>>> import datetime
>>> now = datetime.datetime.now()
>>> now
datetime.datetime(2014, 9, 3, 9, 23, 24, 139059)
>>> now.replace(tzinfo=my_tz)
>>> now
datetime.datetime(2014, 9, 3, 9, 23, 24, 139059, tzinfo=<DstTzInfo 'Australia/Sydney' LMT+10:05:00 STD>)
Here's a slightly more concise version of #vbem's solution:
from datetime import datetime as dt
dt.utcnow().astimezone().tzinfo
The only substantive difference is that I replaced datetime.datetime.now(datetime.timezone.utc) with datetime.datetime.utcnow(). For brevity, I also aliased datetime.datetime as dt.
For my purposes, I want the UTC offset in seconds. Here's what that looks like:
dt.utcnow().astimezone().utcoffset().total_seconds()
Avoiding non-standard module (seems to be a missing method of datetime module):
from datetime import datetime
utcOffset_min = int(round((datetime.now() - datetime.utcnow()).total_seconds())) / 60 # round for taking time twice
utcOffset_h = utcOffset_min / 60
assert(utcOffset_min == utcOffset_h * 60) # we do not handle 1/2 h timezone offsets
print 'Local time offset is %i h to UTC.' % (utcOffset_h)
To create an ISO formatted string that includes the ISO representation of your local time zone in Israel (+04:00) :
on a server in Israel:
>>> datetime.now(datetime.now().astimezone().tzinfo).isoformat()
'2021-09-07T01:02.030042+04:00'
This will create a "timezone aware" date object that will compare to any other datetime object in UTC or local time appropriately. But the time zone ISO representation (and the date/time string itself) will change if you ran this on a server in San Francisco at the exact same time, as I did:
on a server in San Francisco, CA, USA (Pacific):
>>> datetime.now(datetime.now().astimezone().tzinfo).isoformat()
'2021-09-06T14:01:02.030042-07:00'
The datetime objects in in both cases would be compatible with each other. So if you subtracted them you'd get a time delta of 0:
On a server anywhere in Python3.6+:
>>> (datetime.fromisoformat('2021-09-06T14:01:02.030042-07:00') -
... datetime.fromisoformat('2021-09-07T01:01:02.030042+04:00'))
datetime.timedelta(0)
Based on Thoku's answer above, here's an answer that resolves the time zone to the nearest half hour (which is relevant for some timezones eg South Australia's) :
from datetime import datetime
round((round((datetime.now()-datetime.utcnow()).total_seconds())/1800)/2)
Based on J. F. Sebastian's answer, you can do this with the standard library:
import time, datetime
local_timezone = datetime.timezone(datetime.timedelta(seconds=-time.timezone))
Tested in 3.4, should work on 3.4+
You may be happy with pendulum
>>> pendulum.datetime(2015, 2, 5, tz='local').timezone.name
'Israel'
Pendulum has a well designed API for manipulating dates. Everything is TZ-aware.
I have also been looking for a simple way to read the local host configuration and get timezone aware local_time based on it. As of python 3.6+ the simplest approach is use dateutil.tz which will read /etc/localtime and assist in getting timezone aware datetime object.
Here is more info on it: https://dateutil.readthedocs.io/en/stable/tz.html
The implementation to accomplish what you're looking for is as follows:
from datetime import datetime
from dateutil import tz
local_time = datetime.now(tz.gettz())
This will provide you the following local_time:
2019-10-18 13:41:06.624536-05:00
Additional Resources I used in researching this topic:
Paul Ganssle Presentation about time zones:
https://www.youtube.com/watch?v=l4UCKCo9FWY
pytz: The Fastest Footgun in the West
https://blog.ganssle.io/articles/2018/03/pytz-fastest-footgun.html
I want to compare UTC timestamps from a log file with local timestamps
If this is your intent, then I wouldn't worry about specifying specific tzinfo parameters or any additional external libraries. Since Python 3.5, the built in datetime module is all you need to create a UTC and a local timestamp automatically.
import datetime
f = "%a %b %d %H:%M:%S %Z %Y" # Full format with timezone
# tzinfo=None
cdatetime = datetime.datetime(2010, 4, 27, 12, 0, 0, 0) # 1. Your example from log
cdatetime = datetime.datetime.now() # 2. Basic date creation (default: local time)
print(cdatetime.strftime(f)) # no timezone printed
# Tue Apr 27 12:00:00 2010
utctimestamp = cdatetime.astimezone(tz=datetime.timezone.utc) # 1. convert to UTC
utctimestamp = datetime.datetime.now(tz=datetime.timezone.utc) # 2. create in UTC
print(utctimestamp.strftime(f))
# Tue Apr 27 17:00:00 UTC 2010
localtimestamp = cdatetime.astimezone() # 1. convert to local [default]
localtimestamp = datetime.datetime.now().astimezone() # 2. create with local timezone
print(localtimestamp.strftime(f))
# Tue Apr 27 12:00:00 CDT 2010
The '%Z' parameter of datetime.strftime() prints the timezone acronym into the timestamp for humans to read.
For simple things, the following tzinfo implementation can be used, which queries the OS for time zone offsets:
import datetime
import time
class LocalTZ(datetime.tzinfo):
_unixEpochOrdinal = datetime.datetime.utcfromtimestamp(0).toordinal()
def dst(self, dt):
return datetime.timedelta(0)
def utcoffset(self, dt):
t = (dt.toordinal() - self._unixEpochOrdinal)*86400 + dt.hour*3600 + dt.minute*60 + dt.second + time.timezone
utc = datetime.datetime(*time.gmtime(t)[:6])
local = datetime.datetime(*time.localtime(t)[:6])
return local - utc
print datetime.datetime.now(LocalTZ())
print datetime.datetime(2010, 4, 27, 12, 0, 0, tzinfo=LocalTZ())
# If you're in the EU, the following datetimes are right on the DST change.
print datetime.datetime(2013, 3, 31, 0, 59, 59, tzinfo=LocalTZ())
print datetime.datetime(2013, 3, 31, 1, 0, 0, tzinfo=LocalTZ())
print datetime.datetime(2013, 3, 31, 1, 59, 59, tzinfo=LocalTZ())
# The following datetime is invalid, as the clock moves directly from
# 01:59:59 standard time to 03:00:00 daylight savings time.
print datetime.datetime(2013, 3, 31, 2, 0, 0, tzinfo=LocalTZ())
print datetime.datetime(2013, 10, 27, 0, 59, 59, tzinfo=LocalTZ())
print datetime.datetime(2013, 10, 27, 1, 0, 0, tzinfo=LocalTZ())
print datetime.datetime(2013, 10, 27, 1, 59, 59, tzinfo=LocalTZ())
# The following datetime is ambigous, as 02:00 can be either DST or standard
# time. (It is interpreted as standard time.)
print datetime.datetime(2013, 10, 27, 2, 0, 0, tzinfo=LocalTZ())
tzlocal from dateutil.
Code example follows. Last string suitable for use in filenames.
>>> from datetime import datetime
>>> from dateutil.tz import tzlocal
>>> str(datetime.now(tzlocal()))
'2015-04-01 11:19:47.980883-07:00'
>>> str(datetime.now(tzlocal())).replace(' ','-').replace(':','').replace('.','-')
'2015-04-01-111947-981879-0700'
>>>
First, note that the question presents an incorrect initialization of an aware datetime object:
>>> local_time=datetime.datetime(2010, 4, 27, 12, 0, 0, 0,
... tzinfo=pytz.timezone('Israel'))
creates an invalid instance. One can see the problem by computing the UTC offset of the resulting object:
>>> print(local_time.utcoffset())
2:21:00
(Note the result which is an odd fraction of an hour.)
To initialize an aware datetime properly using pytz one should use the localize() method as follows:
>>> local_time=pytz.timezone('Israel').localize(datetime.datetime(2010, 4, 27, 12))
>>> print(local_time.utcoffset())
3:00:00
Now, if you require a local pytz timezone as the new tzinfo, you should use the tzlocal package as others have explained, but if all you need is an instance with a correct local time zone offset and abbreviation then tarting with Python 3.3, you can call the astimezone() method with no arguments to convert an aware datetime instance to your local timezone:
>>> local_time.astimezone().strftime('%Y-%m-%d %H:%M %Z %z')
'2010-04-27 05:00 EDT -0400'
now_dt = datetime.datetime.now()
utc_now = datetime.datetime.utcnow()
now_ts, utc_ts = map(time.mktime, map(datetime.datetime.timetuple, (now_dt, utc_now)))
offset = int((now_ts - utc_ts) / 3600)
hope this will help you.
Suppose I have date d like this :
>>> d
datetime(2009, 4, 19, 21, 12, tzinfo=tzoffset(None, -7200))
As you can see, it is "timezone aware", there is an offset of 2 Hour, utctime is
>>> d.utctimetuple()
time.struct_time(tm_year=2009, tm_mon=4, tm_mday=19,
tm_hour=23, tm_min=12, tm_sec=0,
tm_wday=6, tm_yday=109, tm_isdst=0)
So, real UTC date is 19th March 2009 23:12:00, right ?
Now I need to format my date in string, I use
>>> d.strftime('%Y-%m-%d %H:%M:%S.%f')
'2009-04-19 21:12:00.000000'
Which doesn't seems to take this offset into account. How to fix that ?
In addition to what #Slam has already answered:
If you want to output the UTC time without any offset, you can do
from datetime import timezone, datetime, timedelta
d = datetime(2009, 4, 19, 21, 12, tzinfo=timezone(timedelta(hours=-2)))
d.astimezone(timezone.utc).strftime('%Y-%m-%d %H:%M:%S.%f')
See datetime.astimezone in the Python docs.
The reason is python actually formatting your datetime object, not some "UTC at this point of time"
To show timezone in formatting, use %z or %Z.
Look for strf docs for details
This will convert your local time to UTC and print it:
import datetime, pytz
from dateutil.tz.tz import tzoffset
loc = datetime.datetime(2009, 4, 19, 21, 12, tzinfo=tzoffset(None, -7200))
print(loc.astimezone(pytz.utc).strftime('%Y-%m-%d %H:%M:%S.%f') )
(http://pytz.sourceforge.net/)
I couldn't import timezone module (and hadn't much time to know why)
so I set TZ environment variable which override the /etc/localtime information
>>> import os
>>> import datetime
>>> print datetime.datetime.now().strftime('%Y-%m-%d %H:%M')
2019-05-17 11:26
>>> os.environ["TZ"] = "UTC"
>>> print datetime.datetime.now().strftime('%Y-%m-%d %H:%M')
2019-05-17 09:26