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Accepted
NoahVerner
Asked: 2022-08-07 01:14:20 +0800 CST 2022-08-07 01:14:20 +0800 CST

How to subtract 15 minutes from a pandas timestamp that has 'ms' units in Python?

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Suppose you have the following df:

          End Date         Close Price

2022-05-12 09:59:59.999000     0.00711
2022-05-12 10:14:59.999000     0.00704
2022-05-12 10:29:59.999000     0.00712

The column ['End Date']was set as the index column of thedf

When executing:

In [1]: df.index[0]

You get:

Out[1]: Timestamp('2022-05-12 09:59:59.999000')

How could you subtract 15 minutes from the value df.index[0]in order to get the following output?

Out[2]: Timestamp('2022-05-12 09:44:59.999000')

python-3.x

2 Answers

  1. Good day,

    The easiest way to do this is using pandas.Timedelta.

    I created a dataframetest in the file "sample2.csv" using the data from your question and set the column "End Date" as index and it is of typedatetime

    import pandas as pd

df = pd.read_csv('sample2.csv', index_col='End Date')
df.index = pd.to_datetime(df.index)
df.to_markdown()

    This returns:

    End Date Close Price
    2022-05-12 09:59:59.999000 0.00711
    2022-05-12 10:14:59.999000 0.00704
    2022-05-12 10:29:59.999000 0.00712

    The only thing to do is

    df.index = df.index - pd.Timedelta(minutes=15)

    Printing again the dataframewe get:

    End Date Close Price
    2022-05-12 09:44:59.999000 0.00711
    2022-05-12 09:59:59.999000 0.00704
    2022-05-12 10:14:59.999000 0.00712
    • 1
  2. Best Answer

    Solved, it was very simple actually:

    In [1]: df.index[0] - pd.DateOffset(minutes=15)

    Out [1]: Timestamp('2022-05-12 09:44:59.999000')

    Source: https://thispointer.com/how-to-add-minutes-to-datetime-in-python/

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