Get Yesterday’s date using Python

Prerequisite: datetime module
In Python, date and time are not a data type of its own, but a module named datetime can be imported to work with the date as well as time. Datetime module comes built into Python, so there is no need to install it externally. 

To work with date, datetime module provides the date class and timedelta class is used to calculate differences in date. Let’s have a look at them.

• Date class: When an object of this class is instantiated, it represents a date in the format YYYY-MM-DD. 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.
  Syntax:

date.today()

• Timedelta class: Python timedelta() function is present under datetime library which is generally used for calculating differences in dates and also can be used for date manipulations in Python. It is one of the easiest ways to perform date manipulations.
  Syntax:

datetime.timedelta(days=0, seconds=0, microseconds=0,
                milliseconds=0, minutes=0, hours=0, weeks=0)

Returns: Date

Below is the implementation 

Python3

# Python program to get
# Yesterday's date


# Import date and timedelta class
# from datetime module
from datetime import date
from datetime import timedelta

# Get today's date
today = date.today()
print("Today is: ", today)

# Yesterday date
yesterday = today - timedelta(days = 1)
print("Yesterday was: ", yesterday)

Output:

Today is:  2019-12-11
Yesterday was:  2019-12-10

You just have to subtract no. of days using ‘timedelta’ that you want to get back in order to get the date from the past.

For example, on subtracting two we will get the date of the day before yesterday. 

Python3

# Python program to get
# Yesterday's date


# Import date and timedelta class
# from datetime module
from datetime import date
from datetime import timedelta


# Get today's date
today = date.today()
print("Today is: ", today)

# Get 2 days earlier
yesterday = today - timedelta(days = 2)
print("Day before yesterday was: ", yesterday)

Output:

Today is:  2019-12-11
Day before yesterday was:  2019-12-09