Differentiation of Python – Date & Time

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A Python program can handle date and time in several ways. Converting between date formats is a common chore for computers. Python’s time and calendar modules help track dates and times. In Python, date and time are not a data type of their own, but a module named datetime can be imported to work with the date as well as time. Python Datetime module comes built into Python, so there is no need to install it externally. Python Datetime module supplies classes to work with date and time

Date class

The date class is used to instantiate date objects in Python. When an object of this class is instantiated, it represents a date in the format YYYY-MM-DD. Constructor of this class needs three mandatory arguments year, month and date.

Constructor syntax:  

class datetime.date(year, month, day)

The arguments must be in the following range –  

• MINYEAR <= year <= MAXYEAR
• 1 <= month <= 12
• 1 <= day <= number of days in the given month and year

Note – If the argument is not an integer it will raise a TypeError and if it is outside the range a ValueError will be raised. 

Example 1: Date object representing date in Python

• Python3

Output: 

Date passed as argument is 1996-12-11

Traceback (most recent call last):
  File "/home/ccabfb570d9bd1dcd11dc4fe55fd6ba2.py", line 14, in 
    my_date = date(1996, 12, 39)
ValueError: day is out of range for month

Traceback (most recent call last):
  File "/home/53b974e10651f1853eee3c004b48c481.py", line 18, in 
    my_date = date('1996', 12, 11)
TypeError: an integer is required (got type str) 

Example 2: Get Current Date

To return the current local date today() function of date class is used. today() function comes with several attributes (year, month and day). These can be printed individually. 

• Python3

Output

Today's date is 2021-08-19

Example 3: Get Today’s Year, Month, and Date

We can get the year, month, and date attributes from the date object using the year, month and date attribute of the date class.

• Python3

Output

Current year: 2021
Current month: 8
Current day: 19

Example 4: Get date from Timestamp

We can create date objects from timestamps y=using the fromtimestamp() method. The timestamp is the number of seconds from 1st January 1970 at UTC to a particular date.

• Python3

Output

Datetime from timestamp: 2029-10-25 16:17:48

Example 5: Convert Date to String

We can convert date object to a string representation using two functions isoformat() and strftime().

• Python3

Output

String Representation 2021-08-19
<class 'str'>

What is Tick?

Time intervals are floating-point numbers in units of seconds. Particular instants in time are expressed in seconds since 00:00:00 hrs January 1, 1970(epoch). There is a popular time module available in Python which provides functions for working with times, and for converting between representations. The function time.time() returns the current system time in ticks since 00:00:00 hrs January 1, 1970(epoch).

Example

#!/usr/bin/python
import time;  # This is required to include time module.

ticks = time.time()
print "Number of ticks since 12:00am, January 1, 1970:", ticks

This would produce a result something as follows −

Number of ticks since 12:00am, January 1, 1970: 7186862.73399

Date arithmetic is easy to do with ticks. However, dates before the epoch cannot be represented in this form. Dates in the far future also cannot be represented this way – the cutoff point is sometime in 2038 for UNIX and Windows.

What is TimeTuple?

Many of Python’s time functions handle time as a tuple of 9 numbers, as shown below −

The above tuple is equivalent to struct_time structure. This structure has following attributes −

Getting current time

To translate a time instant from a seconds since the epoch floating-point value into a time-tuple, pass the floating-point value to a function (e.g., localtime) that returns a time-tuple with all nine items valid.

#!/usr/bin/python
import time;

localtime = time.localtime(time.time())
print "Local current time :", localtime

This would produce the following result, which could be formatted in any other presentable form −

Local current time : time.struct_time(tm_year=2013, tm_mon=7, 
tm_mday=17, tm_hour=21, tm_min=26, tm_sec=3, tm_wday=2, tm_yday=198, tm_isdst=0)

Getting formatted time

You can format any time as per your requirement, but simple method to get time in readable format is asctime() −

#!/usr/bin/python
import time;

localtime = time.asctime( time.localtime(time.time()) )
print "Local current time :", localtime

This would produce the following result −

Local current time : Tue Jan 13 10:17:09 2009

Getting calendar for a month

The calendar module gives a wide range of methods to play with yearly and monthly calendars. Here, we print a calendar for a given month ( Jan 2008 ) −

#!/usr/bin/python
import calendar

cal = calendar.month(2008, 1)
print "Here is the calendar:"
print cal

This would produce the following result −

Here is the calendar:
   January 2008
Mo Tu We Th Fr Sa Su
    1  2  3  4  5  6
 7  8  9 10 11 12 13
14 15 16 17 18 19 20
21 22 23 24 25 26 27
28 29 30 31

The time Module

There is a popular time module available in Python which provides functions for working with times and for converting between representations. Here is the list of all available methods −

Let us go through the functions briefly −

There are following two important attributes available with time module −

The calendar Module

The calendar module supplies calendar-related functions, including functions to print a text calendar for a given month or year.mBy default, calendar takes Monday as the first day of the week and Sunday as the last one. To change this, call calendar.setfirstweekday() function.

Here is a list of functions available with the calendar module −