Python beginner: code only returns if statement, ignores everything else

I know this is simple but I can't get this code to work. No matter the order I put the variables or if/elif statements in, it only returns the if statement regardless of the month.

months = input("Enter a month to find out how many days are in that month, or enter 'exit' to quit the program\n")

months_28 = "February" 
months_30 = "April", "June", "September", "November" 
months_31 = "January", "March", "May", "July", "August", "October", "December"

if months or months.casefold() in months_28:
    print("There are 28 days in", months.capitalize()) 
elif months or months.casefold() in months_30:
    print("There are 30 days in", months.capitalize()) 
elif months or months.casefold() in months_31:
    print("There are 31 days in", months.capitalize()) 
else:
    print("That's not a month")

I also am trying to work a while loop into this too (as reflected in the beginning) and any help there would be greatly appreciated. Cheers