Python datetime

Python has a module named datetime to work with dates and times.

It provides a variety of classes for representing and manipulating dates and times, as well as for formatting and parsing dates and times in a variety of formats.

Example 1: Get Current Date and Time

import datetime

# get the current date and time
now = datetime.datetime.now()

print(now)

Output

2022-12-27 08:26:49.219717

Here, we have imported the datetime module using the import datetime statement.

One of the classes defined in the datetime module is the datetime class.

We then used the now() method to create a datetime object containing the current local date and time.

Example 2: Get Current Date

import datetime

# get current date
current_date = datetime.date.today()

print(current_date)

Output

2022-12-27

In the above example, we have used the today() method defined in the date class to get a date object containing the current local date.

Attributes of datetime Module

We can use the dir() function to get a list containing all attributes of a module.

import datetime

print(dir(datetime))

Output

['MAXYEAR', 'MINYEAR', '__builtins__', '__cached__', '__doc__', '__file__', '__loader__', '__name__', '__package__', '__spec__', '_divide_and_round', 'date', 'datetime', 'datetime_CAPI', 'time', 'timedelta', 'timezone', 'tzinfo']

Among all the attributes of datetime module, the most commonly used classes in the datetime module are:

• datetime.datetime - represents a single point in time, including a date and a time.
• datetime.date - represents a date (year, month, and day) without a time.
• datetime.time - represents a time (hour, minute, second, and microsecond) without a date.
• datetime.timedelta - represents a duration, which can be used to perform arithmetic with datetime objects.

Python datetime.date Class

In Python, we 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(2022, 12, 25)
print(d)

Output

2022-12-25

Here, date() in the above example is a constructor of the date class. The constructor takes three arguments: year, month and day.

Import Only date Class

We can only import the date class from the datetime module. For example,

from datetime import date

d = date(2022, 12, 25)
print(d)

Output

2022-12-25

Here, from datetime import date only imports the date class from the datetime module.

Example 4: Get current date using today()

We can create a date object containing the current date by using the class method named today(). For example,

from datetime import date

# today() to get current date
todays_date = date.today()

print("Today's date =", todays_date)

Output

Today's date = 2022-12-27

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 the fromtimestamp() method.

from datetime import date

timestamp = date.fromtimestamp(1326244364)
print("Date =", timestamp)

Output

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. For example,

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)

Output

Current year: 2022
Current month: 12
Current day: 27

Python datetime.time Class

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)

# time(hour, minute and second)
b = time(11, 34, 56)
print(b)

# time(hour, minute and second)
c = time(hour = 11, minute = 34, second = 56)
print(c)

# time(hour, minute, second, microsecond)
d = time(11, 34, 56, 234566)
print(d)

Output

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 we create the time object, we can easily print its attributes such as hour, minute etc. For example,

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)

Output

Hour = 11
Minute = 34
Second = 56
Microsecond = 0

Here, notice that we haven't passed the microsecond argument. Hence, its default value 0 is printed.

The datetime.datetime Class

The datetime module has a class named datetime 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(2022, 12, 28)
print(a)

# datetime(year, month, day, hour, minute, second, microsecond)
b = datetime(2022, 12, 28, 23, 55, 59, 342380)
print(b)

Output

2022-12-28 00:00:00
2022-12-28 23:55:59.342380

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(2022, 12, 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())

Output

year = 202
month = 12
day = 28
hour = 23
minute = 55
timestamp = 1511913359.34238

Python datetime.timedelta Class

A timedelta object represents the difference between two dates or times. For example,

from datetime import datetime, date

# using date()
t1 = date(year = 2018, month = 7, day = 12)
t2 = date(year = 2017, month = 12, day = 23)

t3 = t1 - t2

print("t3 =", t3)

# using datetime()
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))  

Output

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)

Output

t3 = 14 days, 13:55:39

Here, we have created two timedelta objects t1 and t2, and their difference is printed on the screen.

Example 14: Time duration in seconds

We can get the total number of seconds in a timedelta object using the total_seconds() method.

from datetime import timedelta

t = timedelta(days = 5, hours = 1, seconds = 33, microseconds = 233423)
print("Total seconds =", t.total_seconds())

Output

Total seconds = 435633.233423

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() Method

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.

Let's see an example.

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)

Output

time: 04:34:52
s1: 12/26/2018, 04:34:52
s2: 26/12/2018, 04:34:52

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 example, 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() Method

The strptime() method creates a datetime object from a given string (representing date and time). For example,

from datetime import datetime

date_string = "25 December, 2022"
print("date_string =", date_string)

# use strptime() to create date object
date_object = datetime.strptime(date_string, "%d %B, %Y")

print("date_object =", date_object)

Output

date_string = 25 december, 2022
date_object = 2018-06-21 00:00:00

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, we 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 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"))

Output

Local: 12/27/2022, 09:40:19
NY: 12/27/2022, 04:40:19
London: 12/27/2022, 09:40:19

Here, datetime_NY and datetime_London are datetime objects containing the current date and time of their respective timezone.