Pandas Series dt.dayofyear | Get Day of Year in Pandas

Pandas dt.dayofyear attribute returns the ordinal day of the year in the underlying DateTime data in the given Series object.

Example:

Python3

import pandas as pd

sr = pd.Series(['2012-10-21 09:30', '2019-7-18 12:30', '2008-02-2 10:30',
                '2010-4-22 09:25', '2019-11-8 02:22'])

idx = ['Day 1', 'Day 2', 'Day 3', 'Day 4', 'Day 5']
sr.index = idx
sr = pd.to_datetime(sr)
result = sr.dt.dayofyear
print(result)

Output

Syntax

Syntax: Series.dt.dayofyear

Parameter: None

Returns: Series with integers indicating the day number

How to Get Day of Year for a Date in Pandas Series

To get the day number for a date in the Pandas Series we use the dt.dayofyear method of the Pandas Library in Python. It returns the ordinal day of the year for a date in the Series.

Let us understand it better with an example:

Example:

Use Series.dt.dayofyear attribute to return the ordinal day of the year in the underlying data of the given Series object.

Python3

# importing pandas as pd
import pandas as pd

# Creating the Series
sr = pd.Series(pd.date_range('2012-12-12 12:12',
                       periods = 5, freq = 'M'))

# Creating the index
idx = ['Day 1', 'Day 2', 'Day 3', 'Day 4', 'Day 5']

# set the index
sr.index = idx

# Print the series
print(sr)

Output :

Now we will use the Series.dt.dayofyear attribute to return the ordinal day of the year in the DateTime based data in the given series object.

Python3

# return the day of year
result = sr.dt.dayofyear

# print the result
print(result)

Output :

As we can see in the output, the dt.dayofyear attribute has successfully accessed and returned the day of the year in the underlying data of the given series object.