Calculate the number of days between two dates.

calculate_days.py

from datetime import datetime

def calculate_days(from_date, to_date):
    """
    Calculate the number of days between two dates.

    Parameters:
    from_date (str): The start date in the format 'YYYY-MM-DD'.
    to_date (str): The end date in the format 'YYYY-MM-DD'.

    Returns:
    int: The number of days between the start date and the end date.

    Example:
    >>> calculate_days('2025-01-27', '2025-12-31')
    338
    """
    
    # Convert from_date and to_date strings to datetime objects
    from_date = datetime.strptime(from_date, "%Y-%m-%d")
    to_date = datetime.strptime(to_date, "%Y-%m-%d")
    
    # Calculate the difference in days
    difference = to_date - from_date
    
    return difference.days

# Example usage
from_date = "2025-01-27"
to_date = "2025-12-31"
days_difference = calculate_days(from_date, to_date)
print(f"The number of days from {from_date} to {to_date} is {days_difference} days.")