Python Program to Validate a Date

This python program will validate whether a given date is valid or not, based on the input provided by the user.

Problem Statement

Given a date in the format of day, month, and year, we need to check whether the date is valid or not. If the date is valid, the program will display a message indicating that the date is valid. Otherwise, it will display a message stating that the date is invalid.

Python Program to Validate a Date

def is_valid_date(day, month, year):
    # List of maximum days in each month
    max_days = [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]
    
    # Check if it's a leap year
    if year % 4 == 0 and (year % 100 != 0 or year % 400 == 0):
        max_days[1] = 29
    
    # Check if the month is valid
    if month < 1 or month > 12:
        return False
    
    # Check if the day is valid
    if day < 1 or day > max_days[month - 1]:
        return False
    
    return True


# Main program
date_input = input("Enter a date (day, month, year): ")
day, month, year = map(int, date_input.split(','))

if is_valid_date(day, month, year):
    print("The date is valid.")
else:
    print("The date is invalid.")

How it works

The program defines a function called is_valid_date() to check the validity of the given date. It takes three parameters: day, month, and year. The function first creates a list called max_days representing the maximum number of days in each month. By default, February has 28 days.

Next, the function checks if the given year is a leap year. A leap year occurs if the year is divisible by 4 and not divisible by 100, or if it is divisible by 400. If the year is a leap year, it updates the maximum number of days in February to 29.

After that, the function checks if the month is within the valid range of 1 to 12. If the month is invalid, it returns False.

Finally, the function checks if the given day is within the valid range for the given month. It retrieves the maximum number of days for the corresponding month from the max_days list and compares it with the given day. If the day is invalid, it returns False. Otherwise, it returns True to indicate that the date is valid.

In the main program, the user is prompted to enter a date in the format “day, month, year”. The input is then split and converted into integers using the map() function. The program calls the is_valid_date() function with the provided day, month, and year. If the function returns True, it prints “The date is valid.” Otherwise, it prints “The date is invalid.”

Input / Output