RPN - Multiple Conditional Statement?

Does someone knows how to make multiple conditional statements in RPN?
my code looks like this but it doesn’t work

(E:LOCAL MONTH OF YEAR, Number) 12 == if{

(E:LOCAL DAY OF MONTH, Number) 20 >= if{

  (E:LOCAL DAY OF MONTH, Number) 31 <= if{

    1

  }

} els{

  0

}

} els{

0

}