Refactor routine from sequential cohesion to functional cohesion

refactor-routine.php

<?php

//Example of routine with sequential cohesion
function randomRoutineName($birthDate) {
   // Calculate the age from the birth date
   $currentAge = // Stuff to get current age from birth date
   // Calculate the retirement time from the current age
   $retirementTime = // Stuff to get retirement time from current age
}

// Refactor to make this routine above functionally cohesive by separate to two routines
function getAge($birthDate) {
   // Stuff to get current age from birth date
}

function getRetirementTime($currentAge) {
   // Stuff to get retirement time from current age
}
// Now both getAge and getRetirementTime routines have functional cohesion. Other routines could call either routine or both routine