Changing a global variable from inside a function PHP

Question

I am trying to change a variable that is outside of a function, from within a function. Because if the date that the function is checking is over a certain amount I need it

Answer 1

Try this pass by reference

  $var = "01-01-10";
    function checkdate(&$funcVar){  
        if("Condition"){
            $funcVar = "01-01-11";
        }
    }
    checkdate($var);

or Try this same as the above, keeping the function as same.

 $var = "01-01-10";
    function checkdate($funcVar){  
        if("Condition"){
            $funcVar = "01-01-11";
        }
    }
    checkdate(&$var);