$validators = array(
'month' => array(
new Zend_Validate_Between(1, 12),
'messages' => array(
array(
Zend_Validate_Between::NOT_BETWEEN =>
'Month value %value% must be between ' .
'%min% and %max%',
Zend_Validate_Between::NOT_BETWEEN_STRICT =>
'Month value %value% must be strictly between ' .
'%min% and %max%'
)
)
)
);
Done.