Python calendar.monthcalendar() Function

The Python calendar.monthcalendar() function is used to generate a matrix representation of a month's calendar.

This function returns a list of weeks, where each week is a list of integers representing days. Days outside the month are represented by zeros.

Syntax

Following is the syntax of the Python calendar.monthcalendar() function −

calendar.monthcalendar(year, month)

Parameters

This function accepts the following parameters −

• year: The year of the month to be displayed.
• month: The month (1-12) to be displayed.

Return Value

This function returns a list of weeks, where each week is a list of 7 integers. Days that belong to the month are represented by their respective date numbers, and days outside the month are represented by 0.

Example: Getting Month Calendar as a Matrix

In this example, we generate a matrix for March 2025 using the Python calendar.monthcalendar() function −

import calendar

# Generate March 2025 matrix
month_matrix = calendar.monthcalendar(2025, 3)

print(month_matrix)

Following is the output obtained −

[[0, 0, 0, 0, 0, 1, 2],
 [3, 4, 5, 6, 7, 8, 9],
 [10, 11, 12, 13, 14, 15, 16],
 [17, 18, 19, 20, 21, 22, 23],
 [24, 25, 26, 27, 28, 29, 30],
 [31, 0, 0, 0, 0, 0, 0]]

Example: Iterating Over the Calendar Matrix

We can iterate over the matrix to display the month in a readable format as shown in the example below −

import calendar

# Generate March 2025 matrix
month_matrix = calendar.monthcalendar(2025, 3)

for week in month_matrix:
   print(week)

Following is the output of the above code −

[0, 0, 0, 0, 0, 1, 2]
[3, 4, 5, 6, 7, 8, 9]
[10, 11, 12, 13, 14, 15, 16]
[17, 18, 19, 20, 21, 22, 23]
[24, 25, 26, 27, 28, 29, 30]
[31, 0, 0, 0, 0, 0, 0]

Example: Checking if a Specific Day is in a Week

We can check if a specific date is in a given week using this function −

import calendar

# Generate March 2025 matrix
month_matrix = calendar.monthcalendar(2025, 3)

# Check if 15th is in a particular week
for week in month_matrix:
   if 15 in week:
      print("15th March is in this week:", week)

We get the output as shown below −

15th March is in this week: [10, 11, 12, 13, 14, 15, 16]

Example: Counting Number of Weeks in a Month

We can determine how many weeks exist in a given month using the calendar.monthcalendar() function −

import calendar

# Generate March 2025 matrix
month_matrix = calendar.monthcalendar(2025, 3)

# Count the number of weeks
num_weeks = len(month_matrix)

print("Number of weeks in March 2025:", num_weeks)

The result produced is as follows −

Number of weeks in March 2025: 6