In this article, we are going to work with Datetime objects and learn about their behavior when Time zones are introduced. We are going to be working with the Python datetime module.
Getting a Datetime object
Method 1: Using now() method
A very easy way to get a Datetime object is to use the datetime.now() method. A DateTime object is an instance/object of the datetime.datetime class. The now() method returns an object that represents the current date and time.
Python
# importing datetime moduleimport datetime# getting the datetime object# of current date and timeprint(datetime.datetime.now()) |
Output:
2022-01-17 17:15:50.838373
Method 2: Defining the Datetime object manually
We can also declare the DateTime object manually
Python
# importing datetime moduleimport datetime# initialising the datetime objectobj = datetime.datetime(2001, 12, 9)print(obj) |
Output:
2001-12-09 00:00:00
After this, we learn how to format our Datetime objects.
Formatting DateTime objects
Sometimes we need to print our datetime objects in different formats. For these operations, we are going to use strftime() method. The syntax of strftime() is:
Syntax : strftime(format)
Python
# importing datetime objectimport datetime# initialising datetime objectobj = datetime.datetime(2001, 12, 9)# Example 1print(obj.strftime("%a %m %y"))# Example 2print(obj.strftime("%m-%d-%Y %T:%M%p")) |
Output:
Sun 12 01 12-09-2001 00:00:00:00AM
We can get different attributes of the datetime object. In the code below, we are going to get the hours, minutes, and seconds.
Python
# importing datetime objectimport datetime# initialising datetime objectobj = datetime.datetime(2001, 12, 9, 12, 11, 23)# Hoursprint(obj.hour)# Minutesprint(obj.minute)# Secondsprint(obj.second) |
Output:
12 11 23
We can also get a datetime object using the strptime() method, in which we get a DateTime object from a string. Since the strings we use can be formatted in any form, we need to specify the expected format. To understand this, let’s look at the syntax of strptime():
Syntax : datetime.strptime(data,expected_format)
Parameters :
- data : Our time and date passed as a string in a particular format
- expected_format : the format in which data is presented in the first parameter
Python
# importing datetime objectimport datetime# using strptime() methodprint(datetime.datetime.strptime("Jan 1, 2013 12:30 PM", "%b %d, %Y %I:%M %p")) |
Output:
2013-01-01 12:30:00
Working with Timezones
The DateTime objects that we have been working with till now are what are known as naive DateTime objects. A naive DateTime object does not have any information on the timezone. We can check this using the tzinfo property.
Python
# importing datetime objectimport datetime# defining the objectobj = datetime.datetime(2001, 11, 15, 1, 20, 25)# checking timezone informationprint(obj.tzinfo) |
Output:
None
To set our own timezones, we have to start using the pytz module. In the next example, we will create a DateTime object first and then create a timezone object. We will then localize that timezone object to the DateTime object and check the tzinfo property.
Python
# importing datetime and pytzimport datetimeimport pytz# defining the objectobj = datetime.datetime(2001, 11, 15, 1, 20, 25)# defining the timezonetz = pytz.timezone('Asia/Kolkata')# localising the datetime object# to the timezoneaware_obj = tz.localize(obj)# checking timezone informationprint(aware_obj.tzinfo) |
Output :
Asia/Kolkata
Conversion of DateTime object from one Timezone to another
To convert the DateTime object from one timezone to another we need to use the astimezone() method.
Syntax : DateTimeObject.astimezone(tz=None)
tz : The specified timezone to which the DateTimeObject needs to be converted to
Returns : a datetime instance according to the specified time zone parameter tz
Python
# importing datetime and pytzimport datetimeimport pytz# defining the object and localising it to a timezoneobj = datetime.datetime(2001, 11, 15, 1, 20, 25)tz = pytz.timezone('Asia/Kolkata')obj = tz.localize(obj)# Creating a new timezonenew_tz = pytz.timezone('America/New_York')# Changing the timezone of our objectnew_tz_time = obj.astimezone(new_tz)# Printing out new timeprint(new_tz_time) |
Output:
2001-11-14 14:50:25-05:00
Working with the timedelta class
We can check the difference between two DateTime objects with are either both localized to the same timezone or are naive. In the next example, we are going to create two DateTime objects localized to the same timezone and check their difference. The difference of the time returned should be an object of the timedelta class.
Python
# importing datetime and pytzimport datetimeimport pytz# defining the objectsobj1 = datetime.datetime(2001, 11, 15, 1, 20, 25)obj2 = datetime.datetime(2001, 6, 3, 2, 10, 12)# Defining the timezonetz = pytz.timezone('Asia/Kolkata')# localising the objects to the timezoneobj1 = tz.localize(obj1)obj2 = tz.localize(obj2)# printing the differencesprint(obj2-obj1)print(obj1-obj2)# Checking the object type of the # difference returnedprint(type(obj1-obj2)) |
Output :
-165 days, 0:49:47 164 days, 23:10:13 <class 'datetime.timedelta'>
Not just differences, timedelta objects can also be used for addition. If we add a timedelta object to a datetime object, we get another datetime object that has the timedelta factored in as the difference with the first datetime object. Let’s see the example :
Python
# importing datetime and pytzimport datetimeimport pytz# defining the objectsobj = datetime.datetime(2001, 11, 15, 1, 20, 25)# defining a timedeltadiff = datetime.timedelta(days=90, hours=1)# getting a datetime object# that is 90 days and 1 hour aheadnew_obj = obj+diff# Our final answerprint(new_obj) |
Output:
2002-02-13 02:20:25
