Generate RFC 3339 timestamp in Python [duplicate]

Solution 1:

UPDATE 2021

In Python 3.2 timezone was added to the datetime module allowing you to easily assign a timezone to UTC.

>>> import datetime
>>> n = datetime.datetime.now(datetime.timezone.utc)
>>> n.isoformat()
'2021-07-13T15:28:51.818095+00:00'

previous answer:

Timezones are a pain, which is probably why they chose not to include them in the datetime library.

try pytz, it has the tzinfo your looking for: http://pytz.sourceforge.net/

You need to first create the datetime object, then apply the timezone like as below, and then your .isoformat() output will include the UTC offset as desired:

d = datetime.datetime.utcnow()
d_with_timezone = d.replace(tzinfo=pytz.UTC)
d_with_timezone.isoformat()

'2017-04-13T14:34:23.111142+00:00'

Or, just use UTC, and throw a "Z" (for Zulu timezone) on the end to mark the "timezone" as UTC.

d = datetime.datetime.utcnow() # <-- get time in UTC
print d.isoformat("T") + "Z"

'2017-04-13T14:34:23.111142Z'

Solution 2:

In Python 3.3+:

>>> from datetime import datetime, timezone                                
>>> local_time = datetime.now(timezone.utc).astimezone()
>>> local_time.isoformat()
'2015-01-16T16:52:58.547366+01:00'

On older Python versions, if all you need is an aware datetime object representing the current time in UTC then you could define a simple tzinfo subclass as shown in the docs to represent UTC timezone:

from datetime import datetime

utc_now = datetime.now(utc)
print(utc_now.isoformat('T'))
# -> 2015-05-19T20:32:12.610841+00:00

You could also use tzlocal module to get pytz timezone representing your local timezone:

#!/usr/bin/env python
from datetime import datetime
from tzlocal import get_localzone # $ pip install tzlocal

now = datetime.now(get_localzone())
print(now.isoformat('T'))

It works on both Python 2 and 3.

Solution 3:

On modern (3.x) python, to get RFC 3339 UTC time, all you need to do is use datetime and this single line (no third-party modules necessary):

import datetime
datetime.datetime.now(datetime.timezone.utc).isoformat()

The result is something like: '2019-06-13T15:29:28.972488+00:00'

This ISO 8601 string is also RFC3339 compatible.