Pandas: How to Add/Subtract Time to Datetime

You can use the following basic syntax to add or subtract time to a datetime in pandas:

#add time to datetime
df['new_datetime'] = df['my_datetime'] + pd.Timedelta(hours=5, minutes=10, seconds=3)

#subtract time from datetime
df['new_datetime'] = df['my_datetime'] - pd.Timedelta(hours=5, minutes=10, seconds=3) 

The following example shows how to use this syntax in practice.

Example: Add/Subtract Time to Datetime in Pandas

Suppose we have the following pandas DataFrame that shows the sales made by some store during 10 different datetimes:

import pandas as pd

#create DataFrame
df = pd.DataFrame({'time': pd.date_range('2022-01-01', periods=10),
                   'sales': [14, 22, 25, 29, 31, 10, 12, 8, 22, 25]})

#view DataFrame
print(df)

        time  sales
0 2022-01-01     14
1 2022-01-02     22
2 2022-01-03     25
3 2022-01-04     29
4 2022-01-05     31
5 2022-01-06     10
6 2022-01-07     12
7 2022-01-08      8
8 2022-01-09     22
9 2022-01-10     25

We can use the pandas Timedelta function to add 5 hours, 10 minutes, and 3 seconds to each datetime value in the “time” column:

#create new column that contains time + 5 hours, 10 minutes, 3 seconds
df['time_plus_some'] = df['time'] + pd.Timedelta(hours=5, minutes=10, seconds=3)

#view updated DataFrame
print(df)

        time  sales      time_plus_some
0 2022-01-01     14 2022-01-01 05:10:03
1 2022-01-02     22 2022-01-02 05:10:03
2 2022-01-03     25 2022-01-03 05:10:03
3 2022-01-04     29 2022-01-04 05:10:03
4 2022-01-05     31 2022-01-05 05:10:03
5 2022-01-06     10 2022-01-06 05:10:03
6 2022-01-07     12 2022-01-07 05:10:03
7 2022-01-08      8 2022-01-08 05:10:03
8 2022-01-09     22 2022-01-09 05:10:03
9 2022-01-10     25 2022-01-10 05:10:03

And we can just as easily create a new column that subtracts 5 hours, 10 minutes, and 3 seconds from each datetime value in the “time” column:

#create new column that contains time - 5 hours, 10 minutes, 3 seconds
df['time_minus_some'] = df['time'] - pd.Timedelta(hours=5, minutes=10, seconds=3)

#view updated DataFrame
print(df)

        time  sales     time_minus_some
0 2022-01-01     14 2021-12-31 18:49:57
1 2022-01-02     22 2022-01-01 18:49:57
2 2022-01-03     25 2022-01-02 18:49:57
3 2022-01-04     29 2022-01-03 18:49:57
4 2022-01-05     31 2022-01-04 18:49:57
5 2022-01-06     10 2022-01-05 18:49:57
6 2022-01-07     12 2022-01-06 18:49:57
7 2022-01-08      8 2022-01-07 18:49:57
8 2022-01-09     22 2022-01-08 18:49:57
9 2022-01-10     25 2022-01-09 18:49:57

Note #1: In these examples we used a specific number of hours, minutes, and seconds, but you can also use only one of these units if you’d like. For example, you can specify pd.Timedelta(hours=5) to simply add five hours to a datetime value.

Note #2: You can find the complete documentation for the pandas Timedelta function here.

Additional Resources

The following tutorials explain how to perform other common tasks in pandas:

How to Convert Timedelta to Int in Pandas
How to Convert DateTime to String in Pandas
How to Convert Timestamp to Datetime in Pandas
How to Create Date Column from Year, Month and Day in Pandas