PHP - 根据星期几在ID上设置类

Question

I dont know if this is possible but I want to apply a class to something based on a day of the week in PHP. The code would something like this. It is being used to show which day it is within an opening times section on a page.

<?php

$dayoftheweek=cal_to_jd(CAL_GREGORIAN,date("m"),date("d"),date("Y"));
$whatdayisit=(jddayofweek($dayoftheweek,1));

    if ($whatdayisit === Monday){

        // SET #monday to class open_colour

    }
    else if ($whatdayisit === Tuesday) {

        // SET #tuesday to class open_colour
    }


    //.........


?>

I'm not sure if PHP is the way to do this or is there a better way with JS/JQuery...

ADDITION ****

<?php 

                if ($whatdayisit === Monday){

                echo

                <div class="opening_times_day_orange">Monday</div> <div class="opening_times_times_orange">07:30 - 23:00 </div>

                }
                else {

                  echo

                  <div class="opening_times_day">Monday</div> <div class="opening_times_times">07:30 - 23:00 </div>  
                }

                ?>

Answer 1

I don't fully understand why you would need this, but wouldn't a simple JS solution be any better (if you need it in the front-end anyway):

   switch (new Date().getDay()) {
    case 0:
        day = "Sunday";
        break;
    case 1:
        day = "Monday";
        break;
    case 2:
        day = "Tuesday";
        break;
    case 3:
        day = "Wednesday";
        break;
    case 4:
        day = "Thursday";
        break;
    case 5:
        day = "Friday";
        break;
    case 6:
        day = "Saturday";
        break;
    }

then add the value of day to whatever you need with jquery: http://www.w3schools.com/jquery/html_addclass.asp