day = input("Enter today's day numerically: ")
if "15" in day or "30" in day:
print("It's payday!")
else:
print("Sorry, not a payday.")
Explanation:
Ask the user what day it is and store it in a variable called, day. Write a simple if else statement to check if ut is payday or not. This program can be more advanced by having payday be a variable.