How to get UTC time in Python? - python

How do I get the UTC time, i.e. milliseconds since Unix epoch on Jan 1, 1970?

For Python 2 code, use datetime.utcnow():
from datetime import datetime
datetime.utcnow()
For Python 3, use datetime.now(timezone.utc) (the 2.x solution will technically work, but has a giant warning in the 3.x docs):
from datetime import datetime, timezone
datetime.now(timezone.utc)
For your purposes when you need to calculate an amount of time spent between two dates all that you need is to subtract end and start dates. The results of such subtraction is a timedelta object.
From the python docs:
class datetime.timedelta([days[, seconds[, microseconds[, milliseconds[, minutes[, hours[, weeks]]]]]]])
And this means that by default you can get any of the fields mentioned in it's definition -
days, seconds, microseconds, milliseconds, minutes, hours, weeks. Also timedelta instance has total_seconds() method that:
Return the total number of seconds contained in the duration.
Equivalent to (td.microseconds + (td.seconds + td.days * 24 * 3600) *
106) / 106 computed with true division enabled.

Timezone-aware datetime object, unlike datetime.utcnow():
from datetime import datetime,timezone
now_utc = datetime.now(timezone.utc)
Timestamp in milliseconds since Unix epoch:
datetime.now(timezone.utc).timestamp() * 1000

In the form closest to your original:
import datetime
def UtcNow():
now = datetime.datetime.utcnow()
return now
If you need to know the number of seconds from 1970-01-01 rather than a native Python datetime, use this instead:
return (now - datetime.datetime(1970, 1, 1)).total_seconds()
Python has naming conventions that are at odds with what you might be used to in Javascript, see PEP 8. Also, a function that simply returns the result of another function is rather silly; if it's just a matter of making it more accessible, you can create another name for a function by simply assigning it. The first example above could be replaced with:
utc_now = datetime.datetime.utcnow

import datetime
import pytz
# datetime object with timezone awareness:
datetime.datetime.now(tz=pytz.utc)
# seconds from epoch:
datetime.datetime.now(tz=pytz.utc).timestamp()
# ms from epoch:
int(datetime.datetime.now(tz=pytz.utc).timestamp() * 1000)

Timezone aware with zero external dependencies:
from datetime import datetime, timezone
def utc_now():
return datetime.utcnow().replace(tzinfo=timezone.utc)

From datetime.datetime you already can export to timestamps with method strftime. Following your function example:
import datetime
def UtcNow():
now = datetime.datetime.utcnow()
return int(now.strftime("%s"))
If you want microseconds, you need to change the export string and cast to float like: return float(now.strftime("%s.%f"))

you could use datetime library to get UTC time even local time.
import datetime
utc_time = datetime.datetime.utcnow()
print(utc_time.strftime('%Y%m%d %H%M%S'))

why all reply based on datetime and not time?
i think is the easy way !
import time
nowgmt = time.strftime("%Y-%m-%d %H:%M:%S", time.gmtime())
print(nowgmt)

To be correct, UTC format needs at least the T letter:
>>> a=(datetime.datetime.now(timezone.utc))
>>> a.strftime("%Y-%m-%dT%H:%M:%SZ")
'2022-11-28T16:42:17Z'

Related

Difference between time.time() and datetime.utcnow()

I want to know about the difference between time.time() and datetime.datetime.utcnow(). Does both returns the current UTC time?
The time.time() function returns the number of seconds since the epoch, as seconds. Note that the "epoch" is defined as the start of January 1st, 1970 in UTC. So the epoch is defined in terms of UTC and establishes a global moment in time. No matter where you are "seconds past epoch" (time.time()) returns the same value at the same moment.
You can read more about time here.
Regarding datetime, datetime.datetime.utcnow() returns the current UTC date and time, with tzinfo None. This is like now(), but returns the current UTC date and time, as a naive datetime object. An aware current UTC datetime can be obtained by calling datetime.now(timezone.utc)
Here is some sample output I ran on my computer, converting it to a string as well:
>>> import time
>>> ts = time.time()
>>> print(ts)
1583748843.6486485
>>> import datetime
>>> st = datetime.datetime.fromtimestamp(ts).strftime('%Y-%m-%d %H:%M:%S')
>>> print(st)
2020-03-09 12:14:03
Does both returns the current UTC time?
Yes and no.
The thing is how they return it.
Module datetime and classes in it (including datetime as class, which you use here) are for operating on date and time - thus they store the date/time in a structured form (object) and allow operations on it (methods).
>>> import datetime
>>> datetime.datetime.utcnow()
datetime.datetime(2020, 3, 9, 10, 4, 4, 284553)
While time module is more about straight C-like time operations. In this case: just returning timestamp (seconds from epoch) - as float (not a special class object).
>>> import time
>>> time.time()
1583748064.798787

Python add days in epoch time

How to add days in epoch time in Python
#lssec -a lastupdate -s root -f /etc/security/passwd 2>/dev/null | cut -f2 -d=
1425917335
above command giving me epoch time I want to add 90 days in that time. how do I add days in epoch time?
datetime makes it easy between fromtimestamp, timedelta and timestamp:
>>> import datetime
>>> orig = datetime.datetime.fromtimestamp(1425917335)
>>> new = orig + datetime.timedelta(days=90)
>>> print(new.timestamp())
1433693335.0
On Python 3.2 and earlier, datetime objects don't have a .timestamp() method, so you must change the last line to the less efficient two-stage conversion:
>>> import time
>>> print(time.mktime(new.timetuple()))
The two-stage conversion takes ~10x longer than .timestamp() on my machine, taking ~2.5 µs, vs. ~270 ns for .timestamp(); admittedly still trivial if you aren't doing it much, but if you need to do it a lot, consider it another argument for using modern Python. :-)
If the input is POSIX timestamp then to get +90 days:
DAY = 86400 # POSIX day (exact value)
future_time = epoch_time + 90*DAY
If you want to work with datetime objects then use UTC timezone:
from datetime import datetime, timedelta
utc_time = datetime.utcfromtimestamp(epoch_time)
future_time = utc_time + timedelta(90)
Don't use local time for the date/time arithmetic (avoid naive fromtimestamp(), mktime(), naive_dt.timestamp() if you can help it). To understand when it may fail, read Find if 24 hrs have passed between datetimes - Python.
You can you dateutil.parser as well:
since24Hours = datetime.utcnow() - timedelta(days=1)
since24Hours=dateutil.parser.parse(str(since24Hours))
since24Hours = since24Hours.strftime('%s')
since24Hours=int(since24Hours)*1000

Get time zone information of the system in Python?

I want to get the default timezone (PST) of my system from Python. What's the best way to do that? I'd like to avoid forking another process.
This should work:
import time
time.tzname
time.tzname returns a tuple of two strings: The first is the name of the local non-DST timezone, the second is the name of the local DST timezone.
Example return: ('MST', 'MDT')
Gives a UTC offset like in ThomasH's answer, but takes daylight savings into account.
>>> import time
>>> offset = time.timezone if (time.localtime().tm_isdst == 0) else time.altzone
>>> offset / 60 / 60 * -1
-9
The value of time.timezone or time.altzone is in seconds West of UTC (with areas East of UTC getting a negative value). This is the opposite to how we'd actually like it, hence the * -1.
time.localtime().tm_isdst will be zero if daylight savings is currently not in effect (although this may not be correct if an area has recently changed their daylight savings law).
EDIT: marr75 is correct, I've edited the answer accordingly.
I found this to work well:
import datetime
tz_string = datetime.datetime.now(datetime.timezone.utc).astimezone().tzname()
For me this was able to differentiate between daylight savings and not.
From Python 3.6 you can do:
tz_string = datetime.datetime.now().astimezone().tzname()
Or
tz_string = datetime.datetime.now().astimezone().tzinfo
Reference with more detail: https://stackoverflow.com/a/39079819/4549682
Check out the Python Time Module.
from time import gmtime, strftime
print(strftime("%z", gmtime()))
Pacific Standard Time
The code snippets for calculating offset are incorrect, see http://bugs.python.org/issue7229.
The correct way to handle this is:
def local_time_offset(t=None):
"""Return offset of local zone from GMT, either at present or at time t."""
# python2.3 localtime() can't take None
if t is None:
t = time.time()
if time.localtime(t).tm_isdst and time.daylight:
return -time.altzone
else:
return -time.timezone
This is in all likelihood, not the exact question that the OP asked, but there are two incorrect snippets on the page and time bugs suck to track down and fix.
For Python 3.6+ this can be easily achieved by following code:
import datetime
local_timezone = datetime.datetime.utcnow().astimezone().tzinfo
print(local_timezone)
But with Python < 3.6 calling astimezone() on naive datetime doesn't work. So we've to do it in a slightly different way.
So for Python 3.x,
import datetime
local_timezone = datetime.datetime.now(datetime.timezone.utc).astimezone().tzinfo
print(local_timezone)
Sample Output:
On Netherlands Server(Python 3.6.9):
CEST
On Bangladesh Server(Python 3.8.2):
+06
More details can be found on this thread.
To obtain timezone information in the form of a datetime.tzinfo object, use dateutil.tz.tzlocal():
from dateutil import tz
myTimeZone = tz.tzlocal()
This object can be used in the tz parameter of datetime.datetime.now():
from datetime import datetime
from dateutil import tz
localisedDatetime = datetime.now(tz = tz.tzlocal())
or the tz parameter of datetime object via datetime.datetime.astimezone():
from datetime import datetime
from dateutil import tz
unlocalisedDatetime = datetime.now()
localisedDatetime = unlocalisedDatetime.astimezone(tz = tz.tzlocal())
Getting offset from UTC as timedelta:
from datetime import datetime, timezone
now = datetime.now()
now.replace(tzinfo=timezone.utc) - now.astimezone(timezone.utc)
Or like this (more obscure but also works):
datetime.now(timezone.utc).astimezone().tzinfo.utcoffset(None)
Both solutions give the same result. For example: datetime.timedelta(seconds=7200)
import tzlocal
tz_info = tzlocal.get_localzone() # 'US/Central' or 'Asia/Calcutta'
dt = datetime.now() # 2023-01-15 15:17:24.412430
print(tz_info.localize(dt) # 2023-01-15 15:17:24.412430-06:00
with tzlocal we will be able to get the local timezone.

How do I get the current time?

How do I get the current time?
Use datetime:
>>> import datetime
>>> now = datetime.datetime.now()
>>> now
datetime.datetime(2009, 1, 6, 15, 8, 24, 78915)
>>> print(now)
2009-01-06 15:08:24.789150
For just the clock time without the date:
>>> now.time()
datetime.time(15, 8, 24, 78915)
>>> print(now.time())
15:08:24.789150
To save typing, you can import the datetime object from the datetime module:
>>> from datetime import datetime
Then remove the prefix datetime. from all of the above.
Use time.strftime():
>>> from time import gmtime, strftime
>>> strftime("%Y-%m-%d %H:%M:%S", gmtime())
'2009-01-05 22:14:39'
from datetime import datetime
datetime.now().strftime('%Y-%m-%d %H:%M:%S')
Example output: '2013-09-18 11:16:32'
See list of strftime directives.
Similar to Harley's answer, but use the str() function for a quick-n-dirty, slightly more human readable format:
>>> from datetime import datetime
>>> str(datetime.now())
'2011-05-03 17:45:35.177000'
How do I get the current time in Python?
The time module
The time module provides functions that tell us the time in "seconds since the epoch" as well as other utilities.
import time
Unix Epoch Time
This is the format you should get timestamps in for saving in databases. It is a simple floating-point number that can be converted to an integer. It is also good for arithmetic in seconds, as it represents the number of seconds since Jan 1, 1970, 00:00:00, and it is memory light relative to the other representations of time we'll be looking at next:
>>> time.time()
1424233311.771502
This timestamp does not account for leap-seconds, so it's not linear - leap seconds are ignored. So while it is not equivalent to the international UTC standard, it is close, and therefore quite good for most cases of record-keeping.
This is not ideal for human scheduling, however. If you have a future event you wish to take place at a certain point in time, you'll want to store that time with a string that can be parsed into a datetime object or a serialized datetime object (these will be described later).
time.ctime
You can also represent the current time in the way preferred by your operating system (which means it can change when you change your system preferences, so don't rely on this to be standard across all systems, as I've seen others expect). This is typically user friendly, but doesn't typically result in strings one can sort chronologically:
>>> time.ctime()
'Tue Feb 17 23:21:56 2015'
You can hydrate timestamps into human readable form with ctime as well:
>>> time.ctime(1424233311.771502)
'Tue Feb 17 23:21:51 2015'
This conversion is also not good for record-keeping (except in text that will only be parsed by humans - and with improved Optical Character Recognition and Artificial Intelligence, I think the number of these cases will diminish).
datetime module
The datetime module is also quite useful here:
>>> import datetime
datetime.datetime.now
The datetime.now is a class method that returns the current time. It uses the time.localtime without the timezone info (if not given, otherwise see timezone aware below). It has a representation (which would allow you to recreate an equivalent object) echoed on the shell, but when printed (or coerced to a str), it is in human readable (and nearly ISO) format, and the lexicographic sort is equivalent to the chronological sort:
>>> datetime.datetime.now()
datetime.datetime(2015, 2, 17, 23, 43, 49, 94252)
>>> print(datetime.datetime.now())
2015-02-17 23:43:51.782461
datetime's utcnow
You can get a datetime object in UTC time, a global standard, by doing this:
>>> datetime.datetime.utcnow()
datetime.datetime(2015, 2, 18, 4, 53, 28, 394163)
>>> print(datetime.datetime.utcnow())
2015-02-18 04:53:31.783988
UTC is a time standard that is nearly equivalent to the GMT timezone. (While GMT and UTC do not change for Daylight Savings Time, their users may switch to other timezones, like British Summer Time, during the Summer.)
datetime timezone aware
However, none of the datetime objects we've created so far can be easily converted to various timezones. We can solve that problem with the pytz module:
>>> import pytz
>>> then = datetime.datetime.now(pytz.utc)
>>> then
datetime.datetime(2015, 2, 18, 4, 55, 58, 753949, tzinfo=<UTC>)
Equivalently, in Python 3 we have the timezone class with a utc timezone instance attached, which also makes the object timezone aware (but to convert to another timezone without the handy pytz module is left as an exercise to the reader):
>>> datetime.datetime.now(datetime.timezone.utc)
datetime.datetime(2015, 2, 18, 22, 31, 56, 564191, tzinfo=datetime.timezone.utc)
And we see we can easily convert to timezones from the original UTC object.
>>> print(then)
2015-02-18 04:55:58.753949+00:00
>>> print(then.astimezone(pytz.timezone('US/Eastern')))
2015-02-17 23:55:58.753949-05:00
You can also make a naive datetime object aware with the pytz timezone localize method, or by replacing the tzinfo attribute (with replace, this is done blindly), but these are more last resorts than best practices:
>>> pytz.utc.localize(datetime.datetime.utcnow())
datetime.datetime(2015, 2, 18, 6, 6, 29, 32285, tzinfo=<UTC>)
>>> datetime.datetime.utcnow().replace(tzinfo=pytz.utc)
datetime.datetime(2015, 2, 18, 6, 9, 30, 728550, tzinfo=<UTC>)
The pytz module allows us to make our datetime objects timezone aware and convert the times to the hundreds of timezones available in the pytz module.
One could ostensibly serialize this object for UTC time and store that in a database, but it would require far more memory and be more prone to error than simply storing the Unix Epoch time, which I demonstrated first.
The other ways of viewing times are much more error-prone, especially when dealing with data that may come from different time zones. You want there to be no confusion as to which timezone a string or serialized datetime object was intended for.
If you're displaying the time with Python for the user, ctime works nicely, not in a table (it doesn't typically sort well), but perhaps in a clock. However, I personally recommend, when dealing with time in Python, either using Unix time, or a timezone aware UTC datetime object.
Do
from time import time
t = time()
t - float number, good for time interval measurement.
There is some difference for Unix and Windows platforms.
>>> from time import gmtime, strftime
>>> strftime("%a, %d %b %Y %X +0000", gmtime())
'Tue, 06 Jan 2009 04:54:56 +0000'
That outputs the current GMT in the specified format. There is also a localtime() method.
This page has more details.
The previous answers are all good suggestions, but I find it easiest to use ctime():
In [2]: from time import ctime
In [3]: ctime()
Out[3]: 'Thu Oct 31 11:40:53 2013'
This gives a nicely formatted string representation of the current local time.
The quickest way is:
>>> import time
>>> time.strftime("%Y%m%d")
'20130924'
If you need current time as a time object:
>>> import datetime
>>> now = datetime.datetime.now()
>>> datetime.time(now.hour, now.minute, now.second)
datetime.time(11, 23, 44)
You can use the time module:
>>> import time
>>> print(time.strftime("%d/%m/%Y"))
06/02/2015
The use of the capital Y gives the full year, and using y would give 06/02/15.
You could also use the following code to give a more lengthy time:
>>> time.strftime("%a, %d %b %Y %H:%M:%S")
'Fri, 06 Feb 2015 17:45:09'
.isoformat() is in the documentation, but not yet here
(this is mighty similar to #Ray Vega's answer):
>>> import datetime
>>> datetime.datetime.now().isoformat()
'2013-06-24T20:35:55.982000'
Why not ask the U.S. Naval Observatory, the official timekeeper of the United States Navy?
import requests
from lxml import html
page = requests.get('http://tycho.usno.navy.mil/cgi-bin/timer.pl')
tree = html.fromstring(page.content)
print(tree.xpath('//html//body//h3//pre/text()')[1])
If you live in the D.C. area (like me) the latency might not be too bad...
Using pandas to get the current time, kind of overkilling the problem at hand:
import pandas as pd
print(pd.datetime.now())
print(pd.datetime.now().date())
print(pd.datetime.now().year)
print(pd.datetime.now().month)
print(pd.datetime.now().day)
print(pd.datetime.now().hour)
print(pd.datetime.now().minute)
print(pd.datetime.now().second)
print(pd.datetime.now().microsecond)
Output:
2017-09-22 12:44:56.092642
2017-09-22
2017
9
22
12
44
56
92693
if you are using numpy already then directly you can use numpy.datetime64()
function.
import numpy as np
str(np.datetime64('now'))
for only date:
str(np.datetime64('today'))
or, if you are using pandas already then you can use pandas.to_datetime() function
import pandas as pd
str(pd.to_datetime('now'))
or,
str(pd.to_datetime('today'))
This is what I ended up going with:
>>>from time import strftime
>>>strftime("%m/%d/%Y %H:%M")
01/09/2015 13:11
Also, this table is a necessary reference for choosing the appropriate format codes to get the date formatted just the way you want it (from Python "datetime" documentation here).
datetime.now() returns the current time as a naive datetime object that represents time in the local timezone. That value may be ambiguous e.g., during DST transitions ("fall back"). To avoid ambiguity either UTC timezone should be used:
from datetime import datetime
utc_time = datetime.utcnow()
print(utc_time) # -> 2014-12-22 22:48:59.916417
Or a timezone-aware object that has the corresponding timezone info attached (Python 3.2+):
from datetime import datetime, timezone
now = datetime.now(timezone.utc).astimezone()
print(now) # -> 2014-12-23 01:49:25.837541+03:00
import datetime
date_time = datetime.datetime.now()
date = date_time.date() # Gives the date
time = date_time.time() # Gives the time
print date.year, date.month, date.day
print time.hour, time.minute, time.second, time.microsecond
Do dir(date) or any variables including the package. You can get all the attributes and methods associated with the variable.
>>> import datetime, time
>>> time = time.strftime("%H:%M:%S:%MS", time.localtime())
>>> print time
'00:21:38:20S'
This question doesn't need a new answer just for the sake of it ... a shiny new-ish toy/module, however, is enough justification. That being the Pendulum library, which appears to do the sort of things which arrow attempted, except without the inherent flaws and bugs which beset arrow.
For instance, the answer to the original question:
>>> import pendulum
>>> print(pendulum.now())
2018-08-14T05:29:28.315802+10:00
>>> print(pendulum.now('utc'))
2018-08-13T19:29:35.051023+00:00
There's a lot of standards which need addressing, including multiple RFCs and ISOs, to worry about. Ever get them mixed up; not to worry, take a little look into dir(pendulum.constants) There's a bit more than RFC and ISO formats there, though.
When we say local, though what do we mean? Well I mean:
>>> print(pendulum.now().timezone_name)
Australia/Melbourne
>>>
Presumably most of the rest of you mean somewhere else.
And on it goes. Long story short: Pendulum attempts to do for date and time what requests did for HTTP. It's worth consideration, particularly for both its ease of use and extensive documentation.
By default, now() function returns output in the YYYY-MM-DD HH:MM:SS:MS format. Use the below sample script to get the current date and time in a Python script and print results on the screen. Create file getDateTime1.py with the below content.
import datetime
currentDT = datetime.datetime.now()
print (str(currentDT))
The output looks like below:
2018-03-01 17:03:46.759624
Try the arrow module from http://crsmithdev.com/arrow/:
import arrow
arrow.now()
Or the UTC version:
arrow.utcnow()
To change its output, add .format():
arrow.utcnow().format('YYYY-MM-DD HH:mm:ss ZZ')
For a specific timezone:
arrow.now('US/Pacific')
An hour ago:
arrow.utcnow().replace(hours=-1)
Or if you want the gist.
arrow.get('2013-05-11T21:23:58.970460+00:00').humanize()
>>> '2 years ago'
Current time of a timezone
from datetime import datetime
import pytz
tz_NY = pytz.timezone('America/New_York')
datetime_NY = datetime.now(tz_NY)
print("NY time:", datetime_NY.strftime("%H:%M:%S"))
tz_London = pytz.timezone('Europe/London')
datetime_London = datetime.now(tz_London)
print("London time:", datetime_London.strftime("%H:%M:%S"))
tz_India = pytz.timezone('Asia/India')
datetime_India = datetime.now(tz_India)
print("India time:", datetime_India.strftime("%H:%M:%S"))
#list timezones
pytz.all_timezones
To get exactly 3 decimal points for milliseconds 11:34:23.751 run this:
def get_time_str(decimal_points=3):
return time.strftime("%H:%M:%S", time.localtime()) + '.%d' % (time.time() % 1 * 10**decimal_points)
More context:
I want to get the time with milliseconds. A simple way to get them:
import time, datetime
print(datetime.datetime.now().time()) # 11:20:08.272239
# Or in a more complicated way
print(datetime.datetime.now().time().isoformat()) # 11:20:08.272239
print(datetime.datetime.now().time().strftime('%H:%M:%S.%f')) # 11:20:08.272239
# But do not use this:
print(time.strftime("%H:%M:%S.%f", time.localtime()), str) # 11:20:08.%f
But I want only milliseconds, right? The shortest way to get them:
import time
time.strftime("%H:%M:%S", time.localtime()) + '.%d' % (time.time() % 1 * 1000)
# 11:34:23.751
Add or remove zeroes from the last multiplication to adjust number of decimal points, or just:
def get_time_str(decimal_points=3):
return time.strftime("%H:%M:%S", time.localtime()) + '.%d' % (time.time() % 1 * 10**decimal_points)
If you just want the current timestamp in ms (for example, to measure execution time), you can also use the "timeit" module:
import timeit
start_time = timeit.default_timer()
do_stuff_you_want_to_measure()
end_time = timeit.default_timer()
print("Elapsed time: {}".format(end_time - start_time))
You can use this function to get the time (unfortunately it doesn't say AM or PM):
def gettime():
from datetime import datetime
return ((str(datetime.now())).split(' ')[1]).split('.')[0]
To get the hours, minutes, seconds and milliseconds to merge later, you can use these functions:
Hour:
def gethour():
from datetime import datetime
return (((str(datetime.now())).split(' ')[1]).split('.')[0]).split(':')[0]
Minute:
def getminute():
from datetime import datetime
return (((str(datetime.now())).split(' ')[1]).split('.')[0]).split(':')[1]
Second:
def getsecond():
from datetime import datetime
return (((str(datetime.now())).split(' ')[1]).split('.')[0]).split(':')[2]
Millisecond:
def getmillisecond():
from datetime import datetime
return (str(datetime.now())).split('.')[1]
You can try the following
import datetime
now = datetime.datetime.now()
print(now)
or
import datetime
now = datetime.datetime.now()
print(now.strftime("%Y-%b-%d, %A %I:%M:%S"))
Because no one has mentioned it yet, and this is something I ran into recently... a pytz timezone's fromutc() method combined with datetime's utcnow() is the best way I've found to get a useful current time (and date) in any timezone.
from datetime import datetime
import pytz
JST = pytz.timezone("Asia/Tokyo")
local_time = JST.fromutc(datetime.utcnow())
If all you want is the time, you can then get that with local_time.time().
import datetime
todays_date = datetime.date.today()
print(todays_date)
>>> 2019-10-12
# adding strftime will remove the seconds
current_time = datetime.datetime.now().strftime('%H:%M')
print(current_time)
>>> 23:38
Method1: Getting Current Date and Time from system datetime
The datetime module supplies classes for manipulating dates and times.
Code
from datetime import datetime,date
print("Date: "+str(date.today().year)+"-"+str(date.today().month)+"-"+str(date.today().day))
print("Year: "+str(date.today().year))
print("Month: "+str(date.today().month))
print("Day: "+str(date.today().day)+"\n")
print("Time: "+str(datetime.today().hour)+":"+str(datetime.today().minute)+":"+str(datetime.today().second))
print("Hour: "+str(datetime.today().hour))
print("Minute: "+str(datetime.today().minute))
print("Second: "+str(datetime.today().second))
print("MilliSecond: "+str(datetime.today().microsecond))
Output will be like
Date: 2020-4-18
Year: 2020
Month: 4
Day: 18
Time: 19:30:5
Hour: 19
Minute: 30
Second: 5
MilliSecond: 836071
Method2: Getting Current Date and Time if Network is available
urllib package helps us to handle the url's that means webpages. Here we collects data from the webpage http://just-the-time.appspot.com/ and parses dateime from the webpage using the package dateparser.
Code
from urllib.request import urlopen
import dateparser
time_url = urlopen(u'http://just-the-time.appspot.com/')
datetime = time_url.read().decode("utf-8", errors="ignore").split(' ')[:-1]
date = datetime[0]
time = datetime[1]
print("Date: "+str(date))
print("Year: "+str(date.split('-')[0]))
print("Month: "+str(date.split('-')[1]))
print("Day: "+str(date.split('-')[2])+'\n')
print("Time: "+str(time))
print("Hour: "+str(time.split(':')[0]))
print("Minute: "+str(time.split(':')[1]))
print("Second: "+str(time.split(':')[2]))
Output will be like
Date: 2020-04-18
Year: 2020
Month: 04
Day: 18
Time: 14:17:10
Hour: 14
Minute: 17
Second: 10
Method3: Getting Current Date and Time from Local Time of the Machine
Python's time module provides a function for getting local time from the number of seconds elapsed since the epoch called localtime(). ctime() function takes seconds passed since epoch as an argument and returns a string representing local time.
Code
from time import time, ctime
datetime = ctime(time()).split(' ')
print("Date: "+str(datetime[4])+"-"+str(datetime[1])+"-"+str(datetime[2]))
print("Year: "+str(datetime[4]))
print("Month: "+str(datetime[1]))
print("Day: "+str(datetime[2]))
print("Week Day: "+str(datetime[0])+'\n')
print("Time: "+str(datetime[3]))
print("Hour: "+str(datetime[3]).split(':')[0])
print("Minute: "+str(datetime[3]).split(':')[1])
print("Second: "+str(datetime[3]).split(':')[2])
Output will be like
Date: 2020-Apr-18
Year: 2020
Month: Apr
Day: 18
Week Day: Sat
Time: 19:30:20
Hour: 19
Minute: 30
Second: 20

Converting datetime to POSIX time

How do I convert a datetime or date object into a POSIX timestamp in python? There are methods to create a datetime object out of a timestamp, but I don't seem to find any obvious ways to do the operation the opposite way.
import time, datetime
d = datetime.datetime.now()
print time.mktime(d.timetuple())
For UTC calculations, calendar.timegm is the inverse of time.gmtime.
import calendar, datetime
d = datetime.datetime.utcnow()
print calendar.timegm(d.timetuple())
Note that Python now (3.5.2) includes a built-in method for this in datetime objects:
>>> import datetime
>>> now = datetime.datetime(2020, 11, 18, 18, 52, 47, 874766)
>>> now.timestamp() # Local time
1605743567.874766
>>> now.replace(tzinfo=datetime.timezone.utc).timestamp() # UTC
1605725567.874766 # 5 hours delta (I'm in UTC-5)
In python, time.time() can return seconds as a floating point number that includes a decimal component with the microseconds. In order to convert a datetime back to this representation, you have to add the microseconds component because the direct timetuple doesn't include it.
import time, datetime
posix_now = time.time()
d = datetime.datetime.fromtimestamp(posix_now)
no_microseconds_time = time.mktime(d.timetuple())
has_microseconds_time = time.mktime(d.timetuple()) + d.microsecond * 0.000001
print posix_now
print no_microseconds_time
print has_microseconds_time
Best conversion from posix/epoch to datetime timestamp and the reverse:
this_time = datetime.datetime.utcnow() # datetime.datetime type
epoch_time = this_time.timestamp() # posix time or epoch time
this_time = datetime.datetime.fromtimestamp(epoch_time)
It depends
Is your datetime object timezone aware or naive?
Timezone Aware
If it is aware it's simple
from datetime import datetime, timezone
aware_date = datetime.now(tz=timezone.utc)
posix_timestamp = aware_date.timestamp()
as date.timestamp() gives you "POSIX timestamp"
NOTE: more accurate to call it an epoch/unix timestamp as it may not be POSIX compliant
Timezone Naive
If it's not timezone aware (naive), then you'd need to know what timezone it was originally in so we can use replace() to convert it into a timezone aware date object. Let's assume that you've stored/retrieved it as UTC Naive. Here we create one, as an example:
from datetime import datetime, timezone
naive_date = datetime.utcnow() # this date is naive, but is UTC based
aware_date = naive_date.replace(tzinfo=timezone.utc) # this date is no longer naive
# now we do as we did with the last one
posix_timestamp = aware_date.timestamp()
It's always better to get to a timezone aware date as soon as you can to prevent issues that can arise with naive dates (as Python will often assume they are local times and can mess you up)
NOTE: also be careful with your understanding of the epoch as it is platform dependent

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