$c=$w%24;
if($c==0){$c=24;}#nobody says 0 o'clock instead of 12 o'clock do they? >:)
$r=ceil($w/24);
$n=(($c-1)*16)+$r;

##</code><code>##

int c=w%24;
double r=Math.ceil(w/24);
if(c==0){c=24;}
Double d=new Double(((c-1)*16)+r);//This line and the next line are necessary because ceil() returns a double
int n=d.intValue();