Python Datetime - A Guide to Work With Dates and Times in Python

Python Date and time Module

There is a Python module that is comprised of various functions to deal, manipulate, and work with dates and date objects. This module is known as the Python datetime module. We can simply start working with dates by importing this module and using the functions and classes it provides.

Current Date and Time with Datetime in Python

Let us see how with the help of the Python datetime module and a simple line of code we can get the current date in Python.

Python Datetime Example:

#import datetime python
import datetime
a = datetime.datetime.now()
print(a)

When the above code block is executed, it will display the current date (containing year, month, day, hour, minute, second, and microsecond in the same order). In the ‘datetime.datetime’ statement, the first datetime is the module and the second one is the datetime class inside of the datetime method which contains information from both date and time objects.

We can also display just one of the attributes of date in python, such as, just the year.

Example:

import datetime
a = datetime.datetime.now()
print(a.year)

Creating Date Objects in Python

In certain cases, we will want to create a custom date instead of just displaying the current date. In those cases, we can use the datetime() class constructor of the Python datetime module.

This Python datetime() class constructor requires three parameters to create a date, that is, year, month, and day.

Example:

import datetime
a = datetime(2050,11,11)
print(a)

Output:
2050-11-11

The Python datetime() class constructor also takes parameters for time and timezone, which are hour, minute, second, microsecond, and tzone. But these parameters are optionally and rarely used. The default value of these parameters is set to 0.

The strftime() Method: Convert String to Datetime in Python

The datetime module in Python also has a method to convert the date objects into readable strings. So, we can display the month or day in a readable string format instead of numerical representation.

Example:

import datetime
a = datetime.datetime(2020,6,19)
print(a.strftime(“%d”), a.strftime(“%B”))

Output:
19, June

Now, we might be wondering, how do we specify that we want to display the month in a readable string format and what ‘%B’ and ‘%d’ are. Well, Python uses C style formatting to generate new strings. These are called format codes. There are different format codes for different attributes of the date object.

The following table contains a list of all legal format codes and their short descriptions:

We can use any of these codes with the strf method to display their respective values. The strftime method can take one or more than one format codes as argument, as shown in our example, where we have used ‘%B’ to display the full version of the month name in a readable string format and ‘%d’ to display the day of the month in a numerical format.

The strptime() Method: Convert Datetime to String in Python

The strptime() method creates a datetime object from the given string.This method takes the string to be converted and the format code as arguments. It’s not possible to create a datetime object from every string. The string has to be in a certain format.

from datetime import datetime
date_str = "21 June, 2018"
print("Date String =", date_str)
print("Type of Date String =", type(date_str))
date_object = datetime.strptime(date_str, "%d %B, %Y")
print("date_object =", date_object)
print("type of date_object =", type(date_object))

The output will be
Date String = 21 June, 2018
Type of Date String = <class 'str'>
date_object = 2018-06-21 00:00:00
type of date_object = <class 'datetime.datetime'>

Timestamp to Datetime and vice-versa in Python

A Unix timestamp is the number of seconds between a particular date and January 1, 1970, at UTC.

Python Timestamp to Datetime

Here, we used the datetime.fromtimestamp() classmethod which returns the datetime object. This object is stored in the dt_object variable.

from datetime import datetime
timestamp = 1545730073
dt_object = datetime.fromtimestamp(timestamp)
print("dt_object =", dt_object)
print("type(dt_object) =", type(dt_object))

The output will be
dt_object = 2018-12-25 09:27:53
type(dt_object) = <class 'datetime.datetime'>

Python Datetime to Timestamp

You can get the timestamp from a datetime object using datetime.timestamp() method.

from datetime import datetime
now = datetime.now()
timestamp = datetime.timestamp(now)
print("timestamp =", timestamp)

The output will be the timestamp for the current datetime.

With this, we come to the end of this module in Python Tutorial. Here we have learned about dealing with dates and time in Python with the help of datetime module. Now, if you want to know, how python can be used for data science, you can go through this blog on python data science tutorial.

Further, check out our offers for Python training Courses and also refer to the trending Python coding interview questions prepared by the industry experts.