Calendar Functions in Python -(monthrange(), prcal(), weekday()?)

Python's calendar module provides useful functions for working with dates and calendars. We'll explore three key methods: monthrange(), prcal(), and weekday() for date calculations and calendar display.

calendar.monthrange(year, month)

The monthrange() method returns a tuple containing the starting weekday number (0=Monday, 6=Sunday) and the number of days in the specified month ?

Example

import calendar

# Getting month information for January 2019
year = 2019
month = 1

weekday, no_of_days = calendar.monthrange(year, month)
print(f'First weekday of the month: {weekday}')
print(f'Number of days: {no_of_days}')

# Let's also check what weekday 1 means
weekdays = ['Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday', 'Sunday']
print(f'January 1, 2019 starts on: {weekdays[weekday]}')

First weekday of the month: 1
Number of days: 31
January 1, 2019 starts on: Tuesday

calendar.prcal(year)

The prcal() method prints the entire year's calendar directly to the console without requiring a print statement ?

Example

import calendar

# Print calendar for 2024
year = 2024
calendar.prcal(year)

                                  2024

      January                   February                   March
Mo Tu We Th Fr Sa Su      Mo Tu We Th Fr Sa Su      Mo Tu We Th Fr Sa Su
 1  2  3  4  5  6  7                1  2  3  4                   1  2  3
 8  9 10 11 12 13 14       5  6  7  8  9 10 11       4  5  6  7  8  9 10
15 16 17 18 19 20 21      12 13 14 15 16 17 18      11 12 13 14 15 16 17
22 23 24 25 26 27 28      19 20 21 22 23 24 25      18 19 20 21 22 23 24
29 30 31                  26 27 28 29               25 26 27 28 29 30 31

       April                      May                       June
Mo Tu We Th Fr Sa Su      Mo Tu We Th Fr Sa Su      Mo Tu We Th Fr Sa Su
 1  2  3  4  5  6  7             1  2  3  4  5                      1  2
 8  9 10 11 12 13 14       6  7  8  9 10 11 12       3  4  5  6  7  8  9
15 16 17 18 19 20 21      13 14 15 16 17 18 19      10 11 12 13 14 15 16
22 23 24 25 26 27 28      20 21 22 23 24 25 26      17 18 19 20 21 22 23
29 30                     27 28 29 30 31            24 25 26 27 28 29 30

        July                     August                  September
Mo Tu We Th Fr Sa Su      Mo Tu We Th Fr Sa Su      Mo Tu We Th Fr Sa Su
 1  2  3  4  5  6  7                1  2  3  4                         1
 8  9 10 11 12 13 14       5  6  7  8  9 10 11       2  3  4  5  6  7  8
15 16 17 18 19 20 21      12 13 14 15 16 17 18       9 10 11 12 13 14 15
22 23 24 25 26 27 28      19 20 21 22 23 24 25      16 17 18 19 20 21 22
29 30 31                  26 27 28 29 30 31         23 24 25 26 27 28 29
                                                    30

      October                   November                  December
Mo Tu We Th Fr Sa Su      Mo Tu We Th Fr Sa Su      Mo Tu We Th Fr Sa Su
    1  2  3  4  5  6                   1  2  3                         1
 7  8  9 10 11 12 13       4  5  6  7  8  9 10       2  3  4  5  6  7  8
14 15 16 17 18 19 20      11 12 13 14 15 16 17       9 10 11 12 13 14 15
21 22 23 24 25 26 27      18 19 20 21 22 23 24      16 17 18 19 20 21 22
28 29 30 31               25 26 27 28 29 30         23 24 25 26 27 28 29
                                                    30 31

calendar.weekday(year, month, day)

The weekday() method returns the weekday number (0=Monday, 6=Sunday) for a specific date ?

Example

import calendar

# Check what day January 28, 2020 was
year = 2020
month = 1
day = 28

weekday_num = calendar.weekday(year, month, day)
print(f'Weekday number: {weekday_num}')

# Convert to readable day name
weekdays = ['Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday', 'Sunday']
print(f'January 28, 2020 was a {weekdays[weekday_num]}')

# Check multiple dates
dates = [(2024, 12, 25), (2024, 7, 4), (2024, 1, 1)]
for year, month, day in dates:
    day_name = weekdays[calendar.weekday(year, month, day)]
    print(f'{year}-{month:02d}-{day:02d} is a {day_name}')

Weekday number: 1
January 28, 2020 was a Tuesday
2024-12-25 is a Wednesday
2024-07-04 is a Thursday
2024-01-01 is a Monday

Practical Usage

These functions are commonly used together for date calculations ?

import calendar

def analyze_month(year, month):
    # Get month info
    first_weekday, days_in_month = calendar.monthrange(year, month)
    
    # Get last day weekday
    last_weekday = calendar.weekday(year, month, days_in_month)
    
    weekdays = ['Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday', 'Sunday']
    
    print(f'Month {month}/{year}:')
    print(f'- Starts on: {weekdays[first_weekday]}')
    print(f'- Ends on: {weekdays[last_weekday]}')
    print(f'- Has {days_in_month} days')

analyze_month(2024, 2)  # February 2024 (leap year)

Month 2/2024:
- Starts on: Thursday
- Ends on: Thursday
- Has 29 days

Conclusion

Python's calendar module provides essential functions for date calculations. Use monthrange() to get month details, prcal() to display yearly calendars, and weekday() to determine specific weekdays.