Python datetime#
Learn to manipulate date and time in Python with the help of examples.
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#
# 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 below:
2021-06-22 18:01:47.527393
Note: Here, 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#
# 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 below:
2021-06-22
Note: In this program, we have used
today()
method defined in thedate
class to get adate
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 something like below:
['MAXYEAR', 'MINYEAR', '__builtins__', '__cached__', '__doc__', '__file__', '__loader__', '__name__', '__package__', '__spec__', 'date', 'datetime', 'datetime_CAPI', 'sys', '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#
# 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 something like below:
2019-04-13
If 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)
2019-04-13
Example 4: Get current date#
You can create a date
object containing the current date by using a classmethod named today()
. Here’s how:
# Example 4: Get current date
from datetime import date
today = date.today()
print("Current date =", today)
Current date = 2021-06-22
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.
Example 5: Get date from a timestamp#
# Example 5: Get date from a timestamp
from datetime import date
timestamp = date.fromtimestamp(1326244364)
print("Date =", timestamp)
# When you run the program, the output will be something like below:
Date = 2012-01-11
Example 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:
# Example 6: Print today's year, month and day
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)
Current year: 2021
Current month: 6
Current day: 22
datetime.time
#
A time object instantiated from the time
class represents the local time.
Example 7: Time object to represent 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 like below:
a = 00:00:00
b = 11:34:56
c = 11:34:56
d = 11:34:56.234566
Example 8: Print hour, minute, second and microsecond#
Once you create a time
object, you can easily print its attributes such as hour
, minute
etc.
# Example 8: Print hour, minute, second and microsecond
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 program, the output will be like below:
hour = 11
minute = 34
second = 56
microsecond = 0
Note: Notice that we haven’t passed
microsecond
argument. Hence, its default value0
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#
# 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 like below:
2018-11-28 00:00:00
2017-11-28 23:55:59.342380
Note: The first three arguments
year
,month
andday
in thedatetime()
constructor are mandatory.
Example 10: Print year, month, hour, minute and timestamp#
# 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 like below:
year = 2017
month = 11
hour = 23
minute = 55
timestamp = 1511893559.34238
datetime.timedelta
#
A timedelta
object represents the difference between two dates or times.
Example 11: Difference between two dates and 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 like below:
t3 = 201 days, 0:00:00
t6 = -333 days, 1:14:20
type of t3 = <class 'datetime.timedelta'>
type of t6 = <class 'datetime.timedelta'>
Note: Notice, both
t3
andt6
are of<class 'datetime.timedelta'>
type.
Example 12: Difference between two timedelta objects#
# 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 like below:
t3 = 14 days, 13:55:39
Note: Here, we have created two timedelta objects
t1
andt2
, and their difference is printed on the screen.
Example 13: Printing negative timedelta object#
# 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 like below:
t3 = -1 day, 23:59:39
t3 = 0:00:21
Example 14: Time duration in seconds#
You can get the total number of seconds in a timedelta
object using total_seconds()
method.
# Example 14: Time duration in seconds
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 like below:
total seconds = 435633.233423
You 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()
#
# 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 like below:
time: 18:12:42
s1: 06/22/2021, 18:12:42
s2: 22/06/2021, 18:12:42
Here, %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.
Directive |
Meaning |
Example |
---|---|---|
|
year |
[0001,…, 2018, 2019,…, 9999] |
|
month |
[01, 02, …, 11, 12] |
|
day |
[01, 02, …, 30, 31] |
|
hour |
[00, 01, …, 22, 23] |
|
minute |
[00, 01, …, 58, 59] |
|
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()
#
# 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 like below:
date_string = 21 June, 2018
date_object = 2018-06-21 00:00:00
Explanation:
The 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 like below:
Local: 06/22/2021, 18:12:47
NY: 06/22/2021, 08:42:48
London: 06/22/2021, 13:42:48
Note: Here,
datetime_NY
anddatetime_London
are datetime objects containing the current date and time of their respective timezone.