Calculate Time Difference in Python

In this article, you’ll learn how to find the time difference between two-time in Python. For example, we want to measure the execution time of a program. Here, we need to calculate the time difference between the program’s start and end times.

Another example is we may need to capture the time change between the two events. We need to subtract one time/timestamp from another to calculate the time difference between two-time.

After reading this Python article, you’ll learn:

• How to calculate the time interval between the two-time strings.
• get time difference in seconds, minutes, and hours
• Get the time difference between two timestamps in Python

Also, see how to get the difference between two dates in days in Python.

How to get the time difference between two-time in Python

Example: Calculate Time Difference in Python

In this example, we will see how to calculate the seconds and milliseconds between two-time.

from datetime import datetime

# start time
start_time = "2:13:57"
end_time = "11:46:38"

# convert time string to datetime
t1 = datetime.strptime(start_time, "%H:%M:%S")
print('Start time:', t1.time())

t2 = datetime.strptime(end_time, "%H:%M:%S")
print('End time:', t2.time())

# get difference
delta = t2 - t1

# time difference in seconds
print(f"Time difference is {delta.total_seconds()} seconds")

# time difference in milliseconds
ms = delta.total_seconds() * 1000
print(f"Time difference is {ms} milliseconds")

Output:

Start time: 02:13:57
End time: 11:46:38
Time difference is 34361.0 seconds
Time difference is 34361000.0 milliseconds

Get time difference in hours and minutes

Note: To calculate the time difference in minutes and hours use the below formulas.

• First, use the above example to get the time difference in seconds between two-time.
• Next, divide the seconds by 60 to get the get time difference in minutes.
• In the end, divide the seconds by 3600 (60*60) to get the time difference in hours.

Example: To get the time difference in hours and minutes between two-time.

from datetime import datetime

# start time and end time
start_time = datetime.strptime("2:13:57", "%H:%M:%S")
end_time = datetime.strptime("11:46:38", "%H:%M:%S")

# get difference
delta = end_time - start_time

sec = delta.total_seconds()
print('difference in seconds:', sec)

min = sec / 60
print('difference in minutes:', min)

# get difference in hours
hours = sec / (60 * 60)
print('difference in hours:', hours)

Output:

difference in seconds: 34361.0
difference in minutes: 572.6833333333333
difference in hours: 9.544722222222223

Time Difference between two timestamps in Python

A timestamp is encoded information generally used in UNIX, which indicates the date and time at which a particular event has occurred.

Now, let’s see how to find the difference between the two timestamps in hours, minutes, and seconds.

• First, store the start timestamp in the ‘start’ variable and the end timestamp in the ‘end’ variable.
• Next, use the fromtimestamp() method to convert both start and end timestamps to datetime objects. We convert these timestamps to datetime because we want to subtract one timestamp from another.
• Next, subtract datetime2 from datetime1 to get the difference between two timestamps in the form of timedelta
• Next, use the total_seconds() method to get the difference in seconds.

Example 1: Difference between two timestamps in HH:MM:SS format.

from datetime import datetime

# start and end timestamps
start_ts = 1652426243.907874
end_ts = 1652436243.907874

# convert timestamps to datetime object
dt1 = datetime.fromtimestamp(start_ts)
print('Datetime Start:', dt1)
dt2 = datetime.fromtimestamp(end_ts)
print('Datetime End:', dt2)

# Difference between two timestamps
# in hours:minutes:seconds format
delta = dt2 - dt1
print('Difference is:', delta)

Output:

Datetime Start: 2022-05-13 12:47:23.907874
Datetime End: 2022-05-13 15:34:03.907874
Difference is: 2:46:40

The output shows the difference between the two timestamps is 2 hours, 46 minutes, and 40 seconds.

Difference between two timestamps in seconds

Use the below example to get the total seconds between two timestamps.

Example:

from datetime import datetime

# convert timestamps to datetime object
start_ts_ = datetime.fromtimestamp(1652426243.907874)
print('Datetime Start:', start_ts_)
end_ts = datetime.fromtimestamp(1652436243.907874)
print('Datetime End:', end_ts)

# Difference between two timestamps in seconds
delta = end_ts - start_ts_
print('Difference is seconds:', delta.total_seconds())

Output:

Datetime Start: 2022-05-13 12:47:23.907874
Datetime End: 2022-05-13 15:34:03.907874
Difference is seconds: 10000.0