Write a simple Python program to find the whether the user has entered valid date or not. You will ask 3 user inputs: date, month and year. Please assume that user will enter month by its full name (January, February, March, ). However, users are free to enter month as january or January or JANUARY. So, your program should be able to handle all these cases correctly. Make sure that your program considers leap year as well.

Sample Test Data:

Please enter the date: 29

Please enter the month: February

Please enter the year: 2020

Sample Output:

The entered date is valid.

Sample Test Data:

Please enter the date: 29

Please enter the month: February

Please enter the year: 2019

Sample Output:

The entered date is not valid.