How to convert local time string to UTC?

Question

How do I convert a datetime string in local time to a string in UTC time?

I\'m sure I\'ve done this before, but can\'t find it and SO will hopefull

Answer 1

Using http://crsmithdev.com/arrow/

arrowObj = arrow.Arrow.strptime('2017-02-20 10:00:00', '%Y-%m-%d %H:%M:%S' , 'US/Eastern')

arrowObj.to('UTC') or arrowObj.to('local') 

This library makes life easy :)

Answer 2

Briefly, to convert any datetime date to UTC time:

from datetime import datetime

def to_utc(date):
    return datetime(*date.utctimetuple()[:6])

---

Let's explain with an example. First, we need to create a datetime from the string:

>>> date = datetime.strptime("11 Feb 2011 17:33:54 -0800", "%d %b %Y %H:%M:%S %z")

Then, we can call the function:

>>> to_utc(date)
datetime.datetime(2011, 2, 12, 1, 33, 54)

Step by step how the function works:

>>> date.utctimetuple()
time.struct_time(tm_year=2011, tm_mon=2, tm_mday=12, tm_hour=1, tm_min=33, tm_sec=54, tm_wday=5, tm_yday=43, tm_isdst=0)
>>> date.utctimetuple()[:6]
(2011, 2, 12, 1, 33, 54)
>>> datetime(*date.utctimetuple()[:6])
datetime.datetime(2011, 2, 12, 1, 33, 54)

Answer 3

I'm having good luck with dateutil (which is widely recommended on SO for other related questions):

from datetime import *
from dateutil import *
from dateutil.tz import *

# METHOD 1: Hardcode zones:
utc_zone = tz.gettz('UTC')
local_zone = tz.gettz('America/Chicago')
# METHOD 2: Auto-detect zones:
utc_zone = tz.tzutc()
local_zone = tz.tzlocal()

# Convert time string to datetime
local_time = datetime.strptime("2008-09-17 14:02:00", '%Y-%m-%d %H:%M:%S')

# Tell the datetime object that it's in local time zone since 
# datetime objects are 'naive' by default
local_time = local_time.replace(tzinfo=local_zone)
# Convert time to UTC
utc_time = local_time.astimezone(utc_zone)
# Generate UTC time string
utc_string = utc_time.strftime('%Y-%m-%d %H:%M:%S')

(Code was derived from this answer to Convert UTC datetime string to local datetime)

Answer 4

if you prefer datetime.datetime:

dt = datetime.strptime("2008-09-17 14:04:00","%Y-%m-%d %H:%M:%S")
utc_struct_time = time.gmtime(time.mktime(dt.timetuple()))
utc_dt = datetime.fromtimestamp(time.mktime(utc_struct_time))
print dt.strftime("%Y-%m-%d %H:%M:%S")

Answer 5

I've had the most success with python-dateutil:

from dateutil import tz

def datetime_to_utc(date):
    """Returns date in UTC w/o tzinfo"""
    return date.astimezone(tz.gettz('UTC')).replace(tzinfo=None) if date.tzinfo else date

Answer 6

I found the best answer on another question here. It only uses python built-in libraries and does not require you to input your local timezone (a requirement in my case)

import time
import calendar

local_time = time.strptime("2018-12-13T09:32:00.000", "%Y-%m-%dT%H:%M:%S.%f")
local_seconds = time.mktime(local_time)
utc_time = time.gmtime(local_seconds)

I'm reposting the answer here since this question pops up in google instead of the linked question depending on the search keywords.