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Tutorial Reference

Python Pandas: How to Get All Sundays of a Year Using Pandas

Learn how to extract every Sunday (or any weekday) in a year using Pandas' date_range() with weekly frequency codes like W-SUN, including formatting and practical examples.

Finding all occurrences of a specific weekday within a year is a common task in scheduling, reporting, and time-series analysis. Whether you need to count business days, plan weekly events, or build a calendar-based dataset, Pandas' date_range() function handles the calendar logic automatically with weekly frequency codes. It correctly accounts for years that have 52 versus 53 occurrences of a given weekday, so you never have to worry about edge cases.

In this guide, you will learn how to generate all Sundays (or any other weekday) in a year, format the output, and apply the results in practical scenarios.

Basic Usage with date_range()

Use the freq='W-SUN' frequency code to generate all Sundays within a date range:

import pandas as pd

sundays = pd.date_range(start='2024-01-01', end='2024-12-31', freq='W-SUN')

print(f"Number of Sundays in 2024: {len(sundays)}")
print(sundays[:5])

Output:

Number of Sundays in 2024: 52
DatetimeIndex(['2024-01-07', '2024-01-14', '2024-01-21', '2024-01-28',
               '2024-02-04'],
              dtype='datetime64[ns]', freq='W-SUN')

The first Sunday of 2024 falls on January 7th, and Pandas generates every subsequent Sunday through the end of the year.

Frequency Codes for Any Weekday

The W- prefix followed by a three-letter day abbreviation lets you target any day of the week:

Code Day
W-SUN Sunday
W-MON Monday
W-TUE Tuesday
W-WED Wednesday
W-THU Thursday
W-FRI Friday
W-SAT Saturday 
import pandas as pd

fridays = pd.date_range('2024-01-01', '2024-12-31', freq='W-FRI')
print(f"Fridays in 2024: {len(fridays)}")

mondays = pd.date_range('2024-01-01', '2024-12-31', freq='W-MON')
print(f"Mondays in 2024: {len(mondays)}")

Output:

Fridays in 2024: 52
Mondays in 2024: 53

Why Use start/end Instead of periods

Some years have 53 occurrences of a particular weekday while others have 52. Using date boundaries ensures you always get the correct count:

import pandas as pd

sundays_2023 = pd.date_range('2023-01-01', '2023-12-31', freq='W-SUN')
print(f"Sundays in 2023: {len(sundays_2023)}")

sundays_2024 = pd.date_range('2024-01-01', '2024-12-31', freq='W-SUN')
print(f"Sundays in 2024: {len(sundays_2024)}")

Output:

Sundays in 2023: 53
Sundays in 2024: 52

Formatting the Output

Convert the DatetimeIndex to formatted strings for display or export:

import pandas as pd

sundays = pd.date_range('2024-01-01', '2024-12-31', freq='W-SUN')

iso_dates = sundays.strftime('%Y-%m-%d').tolist()
print(iso_dates[:3])

readable = sundays.strftime('%A, %B %d, %Y').tolist()
print(readable[0])

Output:

['2024-01-07', '2024-01-14', '2024-01-21']
Sunday, January 07, 2024

Practical Examples

Building a Sunday Calendar DataFrame

import pandas as pd

sundays = pd.date_range('2024-01-01', '2024-12-31', freq='W-SUN')

df = pd.DataFrame({
    'Date': sundays,
    'Week_Number': sundays.isocalendar().week,
    'Month': sundays.month_name()
})

print(df.head())

Output:

                 Date  Week_Number     Month
2024-01-07 2024-01-07            1   January
2024-01-14 2024-01-14            2   January
2024-01-21 2024-01-21            3   January
2024-01-28 2024-01-28            4   January
2024-02-04 2024-02-04            5  February

Counting Sundays per Month

import pandas as pd

sundays = pd.date_range('2024-01-01', '2024-12-31', freq='W-SUN')

monthly_counts = sundays.to_series().groupby(sundays.month_name()).count()

print(monthly_counts)

Output:

April        4
August       4
December     5
February     4
January      4
July         4
June         5
March        5
May          4
November     4
October      4
September    5
dtype: int64

Filtering to a Specific Month

import pandas as pd

sundays = pd.date_range('2024-01-01', '2024-12-31', freq='W-SUN')

december_sundays = sundays[sundays.month == 12]

for d in december_sundays:
    print(d.strftime('%B %d, %Y'))

Output:

December 01, 2024
December 08, 2024
December 15, 2024
December 22, 2024
December 29, 2024

Reusable Function for Any Weekday

import pandas as pd

def get_weekdays_in_year(year, day_code='W-SUN'):
    """Get all occurrences of a specific weekday in a given year."""
    return pd.date_range(
        start=f'{year}-01-01',
        end=f'{year}-12-31',
        freq=day_code
    )

wednesdays = get_weekdays_in_year(2025, 'W-WED')
print(f"Wednesdays in 2025: {len(wednesdays)}")
print(wednesdays[:3].strftime('%Y-%m-%d').tolist())

Output:

Wednesdays in 2025: 53
['2025-01-01', '2025-01-08', '2025-01-15']

Quick Reference

Goal Code
All Sundays pd.date_range(start, end, freq='W-SUN')
All Mondays pd.date_range(start, end, freq='W-MON')
Format as strings .strftime('%Y-%m-%d')
Convert to list .tolist()
Count occurrences len(result)
Filter by month result[result.month == 12]

Use pd.date_range(start='YYYY-01-01', end='YYYY-12-31', freq='W-SUN') to get all Sundays in a year.

The W- frequency pattern works for any weekday by appending the three-letter abbreviation.

Always use date boundaries (start and end) rather than periods to correctly handle years with varying numbers of a given weekday.

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