Description:
------------
Hi,
I'm trying to use mktime() to calculate when one month is over.

As you can see the day changed at february (which wa fixed by a quick&dirty-really-bad-hack) and May (more untested).

I think the problem with february is that mktime() doesn't know that february only has 28 days?

Test script:
---------------
<?
$now = time();
$a = mktime(1, 0, $now, 1, 1, 1970);
$b = mktime(1, 0, $now, 1 + 1, 1, 1970);
$c = mktime(1, 0, $now, 1, 1 + 28, 1970); //28 days couse this month has only $
$d = mktime(1, 0, $now, 1 + 1, 1 + 28, 1970);
$e = mktime(1, 0, $now, 1 + 2, 1 + 28, 1970);
$f = mktime(1, 0, $now, 1 + 3, 1 + 28, 1970);
$g = mktime(1, 0, $now, 1 + 4, 1 + 28, 1970);
$h = mktime(1, 0, $now, 1 + 5, 1 + 28, 1970);
echo "Now: $now (".date("d.m.Y",$now).")<br>
a: $a (".date("d.m.Y",$a).")<br>
b: $b (".date("d.m.Y",$b).")<br>
c: $c (".date("d.m.Y",$c).")<br>
d: $d (".date("d.m.Y",$d).")<br>
e: $e (".date("d.m.Y",$e).")<br>
f: $f (".date("d.m.Y",$f).")<br>
g: $g (".date("d.m.Y",$g).")<br>
h: $h (".date("d.m.Y",$h).")";
?>

Expected result:
----------------
Now: 1297608181 (13.02.2011)
a: 1297608181 (13.02.2011)
b: 1300286581 (13.03.2011)
c: 1300027381 (10.03.2011)
d: 1302702181 (13.04.2011)
e: 1305121381 (13.05.2011)
f: 1307799781 (13.06.2011)
g: 1310391781 (13.07.2011)
h: 1313070181 (13.08.2011)


Actual result:
--------------
Now: 1297608181 (13.02.2011)
a: 1297608181 (13.02.2011)
b: 1300286581 (16.03.2011)
c: 1300027381 (13.03.2011)
d: 1302702181 (13.04.2011)
e: 1305121381 (11.05.2011)
f: 1307799781 (11.06.2011)
g: 1310391781 (11.07.2011)
h: 1313070181 (11.08.2011)