Description:
------------
It appears that when the PHP binary was compiled against 64-bit libraries,  
mktime() seems to only do minimal error checking of parms. After some additional 
testing, if found the following results:
PHP Code:
$t=mktime(0,0,0,12,3,292277026596); 
var_dump($t); 

$t=mktime(0,0,0,12,3,292277026597); 
var_dump($t); 

$t=mktime(900000000000,900000000000,900000000000,900000000000,900000000000,90000
0000000); 

var_dump($t); 
int(9223372036854655200)
int(-9223372036823360416) 
int(-6044405109589065632)

It appears that once the parm value exceeds the value limit of a long var, the 
function returns a negative value. No warnings are produced. Instead of 
returning FALSE for an error, the function just returns an invalid result.

Some additional info here: http://phpbuilder.com/board/showthread.php?
p=10971046#post10971046

Test script:
---------------
$t=mktime(0,0,0,12,3,292277026596); 
var_dump($t); 

$t=mktime(0,0,0,12,3,292277026597); 
var_dump($t); 

$t=mktime(900000000000,900000000000,900000000000,900000000000,900000000000,900000000000); 

var_dump($t); 
int(9223372036854655200)
int(-9223372036823360416) 
int(-6044405109589065632)

Expected result:
----------------
Return FALSE if parms are invalid.

Actual result:
--------------
Invalid values. Does not return FALSE.