Python provides a module datetime for manipulation of date and time. It consists of following classes,

  • datetime.date : An object of date class specifies a date using year, month and day
  • datetime.time : An object of time class specifies a timestamp using hour, minute, second, microsecond, and tzinfo.
  • datetime.datetime: An object of datetime is a combination of a date and a time.
  • datetime.timedelta: A duration, that represents the difference between two dates or times or datetimes.
  • datetime.tzinfo: It contains the timezone information.

Now to get the difference between two timestamps in python, we will use the datetime module. First we will create start and end datetime objects from the string timestamps. Then we will subtract the datetime objects to get the duration in the datetime.timedelta object. Then using the properties of timedelta object, we will fetch the seconds in between the two timestamps. Let’s understand with some examples,

Python Example 1: Get difference between two timestamps in seconds

Convert the timestamps in string format to datetime objects. Then subtract them and get the timedelta object. Then use the total_seconds() function of timedelta object to get the complete duration between two timestamps in seconds. For example,

from datetime import datetime

date_1 = '24/7/2021 11:13:08'
date_2 = '24/7/2021 11:14:18'

date_format_str = '%d/%m/%Y %H:%M:%S'

start = datetime.strptime(date_1, date_format_str)
end =   datetime.strptime(date_2, date_format_str)

# Get the interval between two datetimes as timedelta object
diff = end - start

print('Difference between two datetimes in seconds:')
print(diff.total_seconds())

Output

Difference between two datetimes in seconds:
70.0

How did it work ?

We created the two datetime objects from the two timestamps in the string format, by passing the date and it’s format in the strptime() function. Then we subtracted these two datetime objects and got the datetime.timedelta object, which represents the duration between two dates. The timedelta class has a member function total_seconds(), which represents the complete duration in seconds (including the fractional part till milliseconds). We used that fetch the difference between two timestamp in seconds.

Python Example 2: Get difference between two dates in seconds

Let’s checkout an another example, where both the timestamps are more than 1 day apart,

from datetime import datetime

date_1 = '24/7/2021 11:13:08'
date_2 = '25/7/2021 11:14:18'

date_format_str = '%d/%m/%Y %H:%M:%S'

start = datetime.strptime(date_1, date_format_str)
end =   datetime.strptime(date_2, date_format_str)

# Get the interval between two datetimes as timedelta object
diff = end - start

print('Difference between two datetimes in seconds:')

print(diff.total_seconds())

Output:

Difference between two datetimes in seconds:
86470.0

The different between ’25/7/2021 11:14:18′ and ’24/7/2021 11:13:08′ is 86470.0 seconds.

If you are not interested in fractional part of seconds, then you can use this also,

print(diff.days * 24 * 60  * 60 +  diff.seconds)

Output:

86470

Here, timedelta.days represents the difference between two timestamp in days and timedelta.seconds represents the seconds that we need to add into the timedelta.days to get the complete difference. Whereas, timedelta.total_seconds() gives the complete interval between two timestamp in seconds.

Python Example 3: Get difference between two timestamps in seconds

Let’s checkout an another example, where both the timestamps are more than 2 years apart,

from datetime import datetime

date_1 = '2/7/2021 21:55:12'
date_2 = '24/9/2023 11:13:08'

date_format_str = '%d/%m/%Y %H:%M:%S'

start = datetime.strptime(date_1, date_format_str)
end =   datetime.strptime(date_2, date_format_str)

# Get the interval between two datetimes as timedelta object
diff = end - start

print('Difference between two datetimes in seconds:')
print(diff.total_seconds())

Output:

Difference between two datetimes in seconds:
70291076.0

The different between ’24/9/2023 11:13:08′ and ‘2/7/2021 21:55:12’ is 70291076.0 seconds.

Python Example 4: Get difference between two datetimes in seconds

If we have complete datetime objects instead of only timestamp strings, in that case lets see how to calculate the difference between two datetimes in seconds,

from datetime import datetime

date_1 = datetime(2021, 7, 2, 21, 55, 12)
date_2 = datetime(2021, 7, 24, 11, 13, 8)

# Get the interval between two datetimes as timedelta object
diff = date_2 - date_1

print('Difference between two datetimes in seconds:')
print(diff.total_seconds())

Output:

Difference between two datetimes in seconds:
1862276.0

Python Example 5: Get difference between two datetimes in seconds using pandas

Suppose we have two timestamps in string format. We can convert them to datetime object using pandas.to_datetime() function. Then we will subtract the datetime objects to get the duration in the datetime.timedelta object. Then using the properties of timedelta object, we will fetch the total seconds in between the two timestamps. For example,

import pandas as pd
from datetime import datetime

date_1 = '2/7/2021 21:55:12'
date_2 = '24/9/2023 11:13:08'

date_format_str = '%d/%m/%Y %H:%M:%S'

start = pd.to_datetime(date_1, format=date_format_str)
end = pd.to_datetime(date_2, format=date_format_str)

# Get the interval between two datetimes as timedelta object
diff = end - start

print('Difference between two datetimes in seconds:')
print(diff.total_seconds())

Output:

Difference between two datetimes in seconds:
70291076.0

Summary:

We learned that, in python how to get the difference between two datetimes in seconds.