Question

I have been using this function for a while without a problem, although I need to add todays date as a class to the <td>. Where would I add this?

/**
 * Returns a HTML calendar
 * 
 * @return HTML table
 */
public function generateCalendar($year, $month, $days = array(), $day_name_length = 3, $month_href = NULL, $first_day = 0, $pn = array(), $hover_content = array()) {
    $first_of_month = gmmktime(0,0,0,$month,1,$year);
    #remember that mktime will automatically correct if invalid dates are entered for instance, mktime(0,0,0,12,32,1997) will be the date for Jan 1, 1998 this provides a built in "rounding" feature to generate_calendar()

    $day_names = array(); #generate all the day names according to the current locale
    for($n=0,$t=(3+$first_day)*86400; $n<7; $n++,$t+=86400) #January 4, 1970 was a Sunday
        $day_names[$n] = ucfirst(gmstrftime('%A',$t)); #%A means full textual day name

    list($month, $year, $month_name, $weekday) = explode(',',gmstrftime('%m,%Y,%B,%w',$first_of_month));
    $weekday = ($weekday + 7 - $first_day) % 7; #adjust for $first_day
    $title   = htmlentities(ucfirst($month_name)).'&nbsp;'.$year;  #note that some locales don't capitalize month and day names

    @list($p, $pl) = each($pn); @list($n, $nl) = each($pn); #previous and next links, if applicable
    if($p) $p = '<span class="calendar-prev">'.($pl ? '<a href="'.htmlspecialchars($pl).'">'.$p.'</a>' : $p).'</span>&nbsp;';
    if($n) $n = '&nbsp;<span class="calendar-next">'.($nl ? '<a href="'.htmlspecialchars($nl).'">'.$n.'</a>' : $n).'</span>';
    $calendar = '<table class="calendar">'.
        '<thead><tr><td colspan="7" class="calendar-month">'.$p.($month_href ? '<a href="'.htmlspecialchars($month_href).'">'.$title.'</a>' : $title).$n."</td><tr>";

    if($day_name_length){ #if the day names should be shown ($day_name_length > 0)
        #if day_name_length is >3, the full name of the day will be printed

        foreach($day_names as $d)
            $calendar .= '<th abbr="'.htmlentities($d).'">'.htmlentities($day_name_length < 4 ? substr($d,0,$day_name_length) : $d).'</th>';
        $calendar .= "</tr>";
    }

    $calendar .= "</thead><tbody><tr>";

    if($weekday > 0) $calendar .= '<td colspan="'.$weekday.'">&nbsp;</td>'; #initial 'empty' days
    for($day=1,$days_in_month=gmdate('t',$first_of_month); $day<=$days_in_month; $day++,$weekday++){
        if($weekday == 7){
            $weekday   = 0; #start a new week
            $calendar .= "</tr><tr>";
        }
        if(isset($days[$day]) and is_array($days[$day])){
            @list($link, $classes, $content) = $days[$day];
            if(is_null($content))  $content  = $day;
            @list($sub_content) = $hover_content[$day];
            $calendar .= '<td'.($classes ? ' class="'.htmlspecialchars($classes).'">' : '>').'<div class="wrapper_div">'.
                '<div class="hoverContent">'.$sub_content.'</div>'.
                ($link ? '<a class="iframe" href="'.htmlspecialchars($link).'">'.$content.'</a>' : $content). '</div></td>';
        }
        else $calendar .= "<td><div>$day</div></td>";
    }
    if($weekday != 7) $calendar .= '<td colspan="'.(7-$weekday).'">&nbsp;</td>'; #remaining "empty" days

    return $calendar."</tr></tbody></table>";
}

Answer 1

This code is ugly – anyway. you can pass a custom class with the third argument called $days.
Simply use getdate and check for the correct month and pass a valid array to the function. I.e.

$days = array();
$date = getdate();
$month = 1;
$year = 2012;

if ($month == $date["mon"]) {
    $days[$date["mday"]] = array(false, "today", null);
}

echo generateCalendar($year, $month, $days);