Python has a module named datetime to work with dates and times. Let's create a few simple programs related to date and time before we dig deeper.
Example 1: Get Current Date and Time
import datetime datetime_object = datetime.datetime.now() print(datetime_object)When you run the program, the output will be something like:
2018-12-19 09:26:03.478039Here, we have imported datetime module using import datetime statement.
One of the classes defined in the datetime module is datetime class. We then used now() method to create a datetime object containing the current local date and time.
Example 2: Get Current Date
import datetime date_object = datetime.date.today() print(date_object)When you run the program, the output will be something like:
2018-12-19In this program, we have used today() method defined in the date class to get a date object containing the current local date.
What's inside datetime?
We can use dir() function to get a list containing all attributes of a module.
import datetime print(dir(datetime))When you run the program, the output will be:
['MAXYEAR', 'MINYEAR', '__builtins__', '__cached__', '__doc__', '__file__', '__loader__', '__name__', '__package__', '__spec__', '_divide_and_round', 'date', 'datetime', 'datetime_CAPI', 'time', 'timedelta', 'timezone', 'tzinfo']Commonly used classes in the datetime module are:
- date Class
- time Class
- datetime Class
- timedelta Class
datetime.date Class
You can instantiate date objects from the date class. A date object represents a date (year, month and day).
Example 3: Date object to represent a date
import datetime d = datetime.date(2019, 4, 13) print(d)When you run the program, the output will be:
2019-04-13If you are wondering, date() in the above example is a constructor of the date class. The constructor takes three arguments: year, month and day.
The variable a is a date object.
We can only import date class from the datetime module. Here's how:
from datetime import date a = date(2019, 4, 13) print(a)Example 4: Get current date
You can create a date object containing the current date by using a classmethod named today(). Here's how:
from datetime import date today = date.today() print("Current date =", today)Example 5: Get date from a timestamp
We can also create date objects from a timestamp. A Unix timestamp is the number of seconds between a particular date and January 1, 1970 at UTC. You can convert a timestamp to date using fromtimestamp() method.
from datetime import date timestamp = date.fromtimestamp(1326244364) print("Date =", timestamp)When you run the program, the output will be:
Date = 2012-01-11Example 6: Print today's year, month and day
We can get year, month, day, day of the week etc. from the date object easily. Here's how:
from datetime import date # date object of today's date today = date.today() print("Current year:", today.year) print("Current month:", today.month) print("Current day:", today.day)datetime.time
A time object instantiated from the time class represents the local time.
Example 7: Time object to represent time
from datetime import time # time(hour = 0, minute = 0, second = 0) a = time() print("a =", a) # time(hour, minute and second) b = time(11, 34, 56) print("b =", b) # time(hour, minute and second) c = time(hour = 11, minute = 34, second = 56) print("c =", c) # time(hour, minute, second, microsecond) d = time(11, 34, 56, 234566) print("d =", d)When you run the program, the output will be:
a = 00:00:00 b = 11:34:56 c = 11:34:56 d = 11:34:56.234566Example 8: Print hour, minute, second and microsecond
Once you create a time object, you can easily print its attributes such as hour, minute etc.
from datetime import time a = time(11, 34, 56) print("hour =", a.hour) print("minute =", a.minute) print("second =", a.second) print("microsecond =", a.microsecond)When you run the example, the output will be:
hour = 11 minute = 34 second = 56 microsecond = 0Notice that we haven't passed microsecond argument. Hence, its default value 0 is printed.
datetime.datetime
The datetime module has a class named dateclass that can contain information from both date and time objects.
Example 9: Python datetime object
from datetime import datetime #datetime(year, month, day) a = datetime(2018, 11, 28) print(a) # datetime(year, month, day, hour, minute, second, microsecond) b = datetime(2017, 11, 28, 23, 55, 59, 342380) print(b)When you run the program, the output will be:
The first three arguments year, month and day in the datetime() constructor are mandatory.
Example 10: Print year, month, hour, minute and timestamp
from datetime import datetime a = datetime(2017, 11, 28, 23, 55, 59, 342380) print("year =", a.year) print("month =", a.month) print("hour =", a.hour) print("minute =", a.minute) print("timestamp =", a.timestamp())When you run the program, the output will be:
year = 2017 month = 11 day = 28 hour = 23 minute = 55 timestamp = 1511913359.34238datetime.timedelta
A timedelta object represents the difference between two dates or times.
Example 11: Difference between two dates and times
from datetime import datetime, date t1 = date(year = 2018, month = 7, day = 12) t2 = date(year = 2017, month = 12, day = 23) t3 = t1 - t2 print("t3 =", t3) t4 = datetime(year = 2018, month = 7, day = 12, hour = 7, minute = 9, second = 33) t5 = datetime(year = 2019, month = 6, day = 10, hour = 5, minute = 55, second = 13) t6 = t4 - t5 print("t6 =", t6) print("type of t3 =", type(t3)) print("type of t6 =", type(t6))When you run the program, the output will be:
t3 = 201 days, 0:00:00 t6 = -333 days, 1:14:20 type of t3 = <class 'datetime.timedelta'> type of t6 = <class 'datetime.timedelta'>Notice, both t3 and t6 are of <class 'datetime.timedelta'> type.
Example 12: Difference between two timedelta objects
from datetime import timedelta t1 = timedelta(weeks = 2, days = 5, hours = 1, seconds = 33) t2 = timedelta(days = 4, hours = 11, minutes = 4, seconds = 54) t3 = t1 - t2 print("t3 =", t3)When you run the program, the output will be:
t3 = 14 days, 13:55:39Here, we have created two timedelta objects t1 and t2, and their difference is printed on the screen.
Example 13: Printing negative timedelta object
from datetime import timedelta t1 = timedelta(seconds = 33) t2 = timedelta(seconds = 54) t3 = t1 - t2 print("t3 =", t3) print("t3 =", abs(t3))When you run the program, the output will be:
t3 = -1 day, 23:59:39 t3 = 0:00:21Example 14: Time duration in seconds
You can get the total number of seconds in a timedelta object using total_seconds() method.
from datetime import timedelta t = timedelta(days = 5, hours = 1, seconds = 33, microseconds = 233423) print("total seconds =", t.total_seconds())When you run the program, the output will be:
total seconds = 435633.233423You can also find sum of two dates and times using + operator. Also, you can multiply and divide a timedelta object by integers and floats.
Python format datetime
The way date and time is represented may be different in different places, organizations etc. It's more common to use mm/dd/yyyy in the US, whereas dd/mm/yyyy is more common in the UK.
Python has strftime() and strptime() methods to handle this.
Python strftime() - datetime object to string
The strftime() method is defined under classes date, datetime and time. The method creates a formatted string from a given date, datetime or time object.
Example 15: Format date using strftime()
from datetime import datetime # current date and time now = datetime.now() t = now.strftime("%H:%M:%S") print("time:", t) s1 = now.strftime("%m/%d/%Y, %H:%M:%S") # mm/dd/YY H:M:S format print("s1:", s1) s2 = now.strftime("%d/%m/%Y, %H:%M:%S") # dd/mm/YY H:M:S format print("s2:", s2)When you run the program, the output will be something like:
time: 04:34:52 s1: 12/26/2018, 04:34:52 s2: 26/12/2018, 04:34:52Here, %Y, %m, %d, %H etc. are format codes. The strftime() method takes one or more format codes and returns a formatted string based on it.
In the above program, t, s1 and s2 are strings.
- %Y - year [0001,..., 2018, 2019,..., 9999]
- %m - month [01, 02, ..., 11, 12]
- %d - day [01, 02, ..., 30, 31]
- %H - hour [00, 01, ..., 22, 23
- %M - minute [00, 01, ..., 58, 59]
- %S - second [00, 01, ..., 58, 59]
To learn more about strftime() and format codes, visit: Python strftime().
Python strptime() - string to datetime
The strptime() method creates a datetime object from a given string (representing date and time).
Example 16: strptime()
from datetime import datetime date_string = "21 June, 2018" print("date_string =", date_string) date_object = datetime.strptime(date_string, "%d %B, %Y") print("date_object =", date_object)When you run the program, the output will be:
date_string = 21 June, 2018 date_object = 2018-06-21 00:00:00The strptime() method takes two arguments:
- a string representing date and time
- format code equivalent to the first argument
By the way, %d, %B and %Y format codes are used for day, month(full name) and year respectively.
Visit Python strptime() to learn more.
Handling timezone in Python
Suppose, you are working on a project and need to display date and time based on their timezone. Rather than trying to handle timezone yourself, we suggest you to use a third-party pytZ module.
from datetime import datetime import pytz local = datetime.now() print("Local:", local.strftime("%m/%d/%Y, %H:%M:%S")) tz_NY = pytz.timezone('America/New_York') datetime_NY = datetime.now(tz_NY) print("NY:", datetime_NY.strftime("%m/%d/%Y, %H:%M:%S")) tz_London = pytz.timezone('Europe/London') datetime_London = datetime.now(tz_London) print("London:", datetime_London.strftime("%m/%d/%Y, %H:%M:%S"))When you run the program, the output will be something like:
Local time: 2018-12-20 13:10:44.260462 America/New_York time: 2018-12-20 13:10:44.260462 Europe/London time: 2018-12-20 13:10:44.260462Here, datetime_NY and datetime_London are datetime objects containing the current date and time of their respective timezone.