Python has various libraries for dealing with time and date. In this article, we will be discussing the
datetime module and how the Python DateTime now function is used.
About the Module
The DateTime module provides date and time, manipulation classes. The DateTime module is a powerful library that allows us to deal with dates and times of different formats. This library will enable us to represent any timezone in the world. The datetime module has two different types of objects:
The aware object identifies itself to the rest of the time objects relatively. It makes use of parameters such as time zones and daylight saving.
The naive object does not consist of proper parameters. Other
datetime objects cannot identify naive objects.
Importing the Module
As of Python 3.10,
datetime is part of the Python Standard Library under the Data Types category.
About Python Datetime.now()
The function now allows us to get the current date and time. It returns your local date and time defined by the module. Try the following demonstrations using our Online Interpreter.
Time Zone (TZ) is the required time zone to be specified. “Greenwich Mean Time (GMT)” is the default parameter. Therefore, it is an optional parameter.
Provides us the current date and time in said format.
Displaying The Current Date & Time
Using Python DateTime now function, you can display the local date and time.
import datetime datetimeObject = datetime.datetime.now() print(datetimeObject)
Using a Python Datetime Object to Retrieve Specific Date & Time Info
Using a single DateTime object, this is all the information we can get.
datetimeObj = datetime.datetime.now() print(datetimeObj) print("Year: ", datetimeObj.year) print("Month: ", datetimeObj.month) print("Date: ", datetimeObj.day) print("Hour: ", datetimeObj.hour) print("Minute: ", datetimeObj.minute) print("Second: ", datetimeObj.second) print("TimeZone info: ", datetimeObj.tzinfo)
2022-04-21 12:16:52.892221 Year: 2022 Month: 4 Date: 21 Hour: 12 Minute: 16 Second: 52 TimeZone info: None
Displaying the Time Without Milliseconds
It is possible to format the displayed time in DateTime. Any required format but be specified using the format specifiers.
import datetime datetime.datetime.now().strftime("%Y-%m-%d %H:%M:%S")
How to Convert Python DateTime object to Milliseconds from Unix Time
import datetime secondsUNIX = datetime.datetime.now().timestamp() print(secondsUNIX)
Converting to ISO Time Format
.isoformat() function, we are able to display the time in ISO format.
import datetime print(datetime.datetime.utcnow().isoformat())
.now() Not Defined (ERROR)
Users may miss out on the fact that it is a method and not a class itself. Therefore, it must be used as a single function call.
The following code attempts to display the date in MM/DD/YYYY format.
from datetime import datetime print str(now.month) + "." + str(now.day) + "." + str(now.year)
name 'now' is not defined
now is not defined in the code.
from datetime import datetime now = datetime.now()
How to Add Hours Using Python DateTime
Addition and subtraction of hours can be used in situations that require ETA. Arithmetic calculations lead to more accuracy rather than predicting manually.
In this demonstration, we are adding 10 hours to the current time using the
from datetime import datetime, timedelta currentTimePlus10 = datetime.now() + timedelta(hours=10)
How To Add Minutes Using Python DateTime
Similar to adding hours, we can also add minutes to the current time using the
Adding 10 minutes to the current time:
from datetime import datetime, timedelta currentTimePlus10 = datetime.now() + timedelta(minutes=10) print(currentTimePlus10)
Implementing Mocks in Python
Mocks in Python are used for unit testing applications with external dependencies. Mocks are created in order to focus on the actual program rather.
The following program attempts to create a mock for the function.
import mock @mock.patch('datetime.date.today') def today(cls): .... return date(2010, 1, 1) ... ... from datetime import date date.today()
datetime.date(2010, 12, 19)
Zulu / Zero Offset in Python UTC DateTime Objects
datetime module doesn’t recognize military timezone calls such as Zulu. However, using
str.replace function we can achieve the same effect.
import datetime dt = datetime.datetime(2022, 4, 23, 12, 0, 0) str(dt).replace('+00:00', 'Z') print(dt)
How to Convert One Time Zone to Another
Time Zone conversion is an essential feature that this module provides. Using the
.astimezone function we can achieve such requirements.
The following program converts from UTC to America/Los Angeles
from datetime import datetime, timezone, ZoneInfo dt_UTC = datetime.now(timezone.utc) dt_LA = dt_UTC.astimezone(tz=datetime.ZoneInfo("America/Los_Angeles")) print(dt_LA)
In the above program,
mock.patch replaces the function
datetime.date.today() with a mock object only if it’s present within the function decorator. Therefore try writing it like this:
import datetime class NewDate(datetime.date): @classmethod def today(cls): return cls(2022, 23, 03) datetime.date = NewDate
How to Create a File Name which has the Current Date and Time?
There are situations where documents or files must be categorized based on the date and time created. For example, orders from customers can be tracked on a day-to-day basis using this method.
Here’s the following Implementation for creating file names with the current date and time information.
import sys from datetime import datetime fileName = datetime.now().strftime("%Y_%m_%d-%I_%M_%S_%p") sys.stdout = open(fileName + '.xml', 'w')
Python time.localtime vs datetime.now
|Using the time module, we can obtain the time of a record.||DateTime also has the feature but only for each day.|
|The time module is considered to be more precise with its data||DateTime stores a particular date and time of a record.|
|The time module is recommended over DateTime due to ambiguity with DST||DateTime module has similar features to the time module. It provides more object-oriented data types. The only downside is that it has limited support for time zones.|
Python datetime.now() vs datetime.today()
|Takes time zone (TZ) as an argument||Doesn’t take any arguments|
|Provides the local date and time.||Also provides the local date and time.|
|If no argument is passed, it provides the same result as ||Functions similar to |
How to Truncate the Time on a DateTime Object?
The following demonstration shows how we can truncate a DateTime object. The output provided is also a DateTime object.
import datetime dt = datetime.datetime.now() dt = dt.replace(hour=0, minute=0, second=0, microsecond=0) print(dt)
FAQs on Python Datetime Now
There isn’t a particular function for rounding off. However, replacing the microseconds to the nearest 10th works.
roundedTime = raw_datetime.replace(microsecond=0)
Using formatting we are able to achieve this.
Passing -1 in the
.AddDays function will subtract one day.
dateForButton = DateTime.Now.AddDays(-1)
We have demonstrated the functionality of the
.now() function. Other functions of the DateTime library have been discussed. The versatility of this module has been demonstrated through numerous examples.