doesn't work sprintf

[eluser]dimaomni[/eluser]
hello, dear experts

I have that piece of code:

Code:

&lt;? for($day_of_month=1; $day_of_month<=31; $day_of_month++) {
        $mark = $dates[$date1 = sprintf('2010-04-d', $day_of_month)];
?&gt;

But must be sprintf('2010-04-percent02d'...

and it involve problem:

A PHP Error was encountered
Severity: Notice
Message: Undefined index: 2010-04-04 etc...

I've just pasted this piece of code in php file and it work ok, but in CI dosen't work


thanks!