After reading this article, you’ll learn how to find the difference between two dates in Python. Also, we’ll see how to calculate the number of days between two dates and datetime objects.
Table of contents
How to Calculate Difference Between Two Dates in Days
Dates can be in any form, such as string, date object, or datetime object. we will see the example of all cases.
Python provides the datetime module to create and manipulate the date and time. The below steps show how to use the datetime module to calculate the difference between two dates in days.
- Import datetime module
Python datetime module provides various functions to create and manipulate the date and time. Use the
from datetime import datetimestatement to import adatetimeclass from a datetime module. - Convert date string to a datetime object
There may be a case in which dates are in a string format. Before calculating the difference in days, we need to convert both date strings to a datetime object.
Use thestrptime(date_str, format)function to convert a date string into a datetime object as per the correspondingformat.
The format codes are standard directives for mentioning the format of the string for parsing. For example, the%Y/%m/%dformat codes are foryyyy-mm-dd - Subtract the date2 from date1
To get the difference between two dates, subtract date2 from date1. A result is a timedelta object. The timedelta represents a duration which is the difference between two dates, time, or datetime instances, to the microsecond resolution.
- Get a difference in days
To get the number of days between two dates, use the
timedelta.daysattribute - Get the difference in seconds
To get a result in seconds, use the
timedelta.secondsattribute
Example: Days between two dates
from datetime import datetime
# dates in string format
str_d1 = '2021/10/20'
str_d2 = '2022/2/20'
# convert string to date object
d1 = datetime.strptime(str_d1, "%Y/%m/%d")
d2 = datetime.strptime(str_d2, "%Y/%m/%d")
# difference between dates in timedelta
delta = d2 - d1
print(f'Difference is {delta.days} days')Output:
Difference is 123 days
Shortcode:
from datetime import datetime as dt
res = (dt.strptime('2022/2/20', "%Y/%m/%d") - dt.strptime('2021/10/20', "%Y/%m/%d")).daysAlso, see:
- Difference between the two dates in months.
- Time Difference between two-time in Python.
- Calculate the business days between two dates in Python.
Difference between two date object
There are cases in which you receive dates in a date object instead of a string. In such cases, you can directly calculate the difference between them by performing the subtraction operation.
Example:
from datetime import date
def get_difference(date1, date2):
delta = date2 - date1
return delta.days
d1 = date(2021, 10, 20)
d2 = date(2022, 2, 20)
days = get_difference(d1, d2)
print(f'Difference is {days} days')Output:
Difference is 123 days
Difference between two datetime object
We need to work with a datetime object instead of a date in some cases. The datetime object contains both date (year-month-day) and time (hours-minutes-seconds) information. Let’s see how to calculate the number of days between two datetime objects.
- First, convert a datetime string to a
datetimeobject using thestrptime()function - Next, calculate the difference by subtracting
datetime1fromdatetime2.
Example:
from datetime import datetime
# datetime in string format
str_dt1 = '2021/10/20 09:15:32.36980'
str_dt2 = '2022/2/20 04:25:42.120450'
# convert string to datetime
dt1 = datetime.strptime(str_dt1, "%Y/%m/%d %H:%M:%S.%f")
dt2 = datetime.strptime(str_dt2, "%Y/%m/%d %H:%M:%S.%f")
# difference between datetime in timedelta
delta = dt2 - dt1
print(f'Difference is {delta.days} days')Output:
Difference is 122 days
Note:
The Python timedelta object considers 24 hours as one day, and For calendar days, you’ll need to round down to the nearest day by removing the partial day on both sides. I.e., we need to set hour, minute, and seconds to zero in both datetime.
Example:
from datetime import datetime
# datetime in string format
str_dt1 = '2021/10/20 09:15:32.36980'
str_dt2 = '2022/2/20 04:25:42.120450'
# convert string to datetime
dt1 = datetime.strptime(str_dt1, "%Y/%m/%d %H:%M:%S.%f")
dt2 = datetime.strptime(str_dt2, "%Y/%m/%d %H:%M:%S.%f")
rounded_dt1 = dt1.replace(hour=0, minute=0, second=0, microsecond=0)
rounded_dt2 = dt2.replace(hour=0, minute=0, second=0, microsecond=0)
delta = (rounded_dt2 - rounded_dt1)
print(delta.days)
