File Handling Operation in Python

Python Calendar Module – Complete Guide with Examples

The calendar module in Python is used for handling dates, monthly calendars, leap-year calculations, and generating entire year calendars. It is part of Python’s standard library, making it extremely useful for date-based applications, schedulers, dashboards, and automation scripts.

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Why Use the Calendar Module?

• To display a month or full year calendar
• To check whether a year is a leap year
• To count leap years between two years
• To get weekday index for any date
• To build scheduling or date-based applications
• To analyze date-related patterns

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Basic Example of Calendar Module

import calendar

# Print calendar of March 2014
print(calendar.month(2014, 3))

# Get first weekday (0 = Monday, 6 = Sunday)
print(calendar.firstweekday())

# Check leap year
if calendar.isleap(2020):
    print("The year is leap year")
else:
    print("The year is not leap year")

# Count total leap years between two years
print(calendar.leapdays(1950, 2000))

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Print Full Year Calendar

print("The calendar of year 2018 is:")
print(calendar.calendar(2018, 2, 1, 6))

Parameter Explanation

• 2018 → Year
• 2 → Space between columns
• 1 → Number of lines per week
• 6 → Number of columns per row

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Useful Calendar Module Functions

1. calendar.month(year, month)

Returns formatted month calendar.

2. calendar.calendar(year)

Displays full year calendar in text format.

3. calendar.isleap(year)

Returns True if the given year is a leap year.

4. calendar.weekday(year, month, day)

Returns the weekday index (0 = Monday … 6 = Sunday).

5. calendar.monthrange(year, month)

Returns a tuple: (first_weekday, total_days_in_month).

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Assignment 1: Calculate Age in Years, Months, Days

Solution by Shiva Sir:

from datetime import date

a = date(date.today().year, date.today().month, date.today().day)
b = date(
    int(input("enter year")),
    int(input("enter month")),
    int(input("enter day"))
)

# Calculate month difference
if a.month > b.month:
    months = a.month - b.month
else:
    months = b.month - a.month

# Year difference
years = a.year - b.year

# Day difference
if a.day > b.day:
    days = a.day - b.day
else:
    days = b.day - a.day

print('{0} years, {1} months, {2} days'.format(years, months, days))

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Assignment 2: Day Before & After Calculator

User enters a number of days; program displays:

• The date before given days
• The date after given days

Hint: Use timedelta from datetime module.

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Assignment 3: Create a Stopwatch

Build a stopwatch where:

• s → Start
• p → Pause
• e → End

Hint: Use time.time() for timestamp calculation.

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Extra Concepts for Better Understanding

1. Get Weekday Name

import calendar
days = ["Monday","Tuesday","Wednesday","Thursday","Friday","Saturday","Sunday"]

print(days[ calendar.weekday(2025, 12, 25) ])

2. Get Total Days in Any Month

import calendar
first, total = calendar.monthrange(2025, 5)
print("Total days:", total)

3. Generate Calendar as a Matrix

print(calendar.monthcalendar(2025, 1))

4. Iterate Through All Weeks of a Month

import calendar

for week in calendar.monthcalendar(2025, 1):
    print(week)

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⭐ Additional Advanced Examples (Added for Extra Depth)

5. Find All Mondays in a Year

import calendar

year = 2025
mondays = []

for month in range(1, 12+1):
    for week in calendar.monthcalendar(year, month):
        if week[0] != 0:   # Monday exists
            mondays.append((year, month, week[0]))

print(mondays)

6. Display Calendar in HTML Format

import calendar

html_calendar = calendar.HTMLCalendar().formatmonth(2025, 3)
print(html_calendar)