A jQuery Timey-Wimey Indicator

A "time indicator" I wrote after finding a 5 year old, unresolved topic on the jQuery forums asking to turn a JavaScript code into jQuery.

HTML

<div id="contain">
    <div id="are-we-open"></div>
    <div id="main">
        We're open from 9am to 5pm, Monday through Friday. 
        It is currently <span id="insert-time"></span> on a <span id="insert-day"></span> <span id="insert-interval"></span>.
    </div>
</div>

CSS

body{
    font-family:sans-serif;
    font-size:16px;
    background:#eee;
    color:#222;
}
#contain{
    display:block;
    margin:20px auto;
    width:440px;
}
    #are-we-open{
        display:block;
        width:400px;
        padding: 20px;
        border-radius: 8px 8px 0px 0px;
        text-align:center;
        color:#fff;
    }
        .open{ 
            background:#819571;
            background-image: -webkit-gradient(linear, 0% 0%, 0% 100%, from(#819571), to(#687D5B));
            background-image: -webkit-linear-gradient(top, #819571, #687D5B); 
            background-image: -moz-linear-gradient(top, #819571, #687D5B);
            background-image: -ms-linear-gradient(top, #819571, #687D5B);
            background-image: -o-linear-gradient(top, #819571, #687D5B);
            text-shadow: 1px 2px #4E5F3B;
            border:#687D5B 1px solid;
        }
        .closed{
            background:#933C35;
            background-image: -webkit-gradient(linear, 0% 0%, 0% 100%, from(#933C35), to(#C44943));
            background-image: -webkit-linear-gradient(bottom, #933C35, #C44943); 
            background-image: -moz-linear-gradient(bottom, #933C35, #C44943);
            background-image: -ms-linear-gradient(bottom, #933C35, #C44943);
            background-image: -o-linear-gradient(bottom, #933C35, #C44943);
            text-shadow: 1px 2px #742D26;
            border:#933C35 1px solid;
        }
    #main{
        display:block;
        width:400px;
        padding: 20px;
        background:#fff;
        border:#fff 1px solid;
        text-align:center;
        line-height:24px;
        box-shadow: 0px 4px 3px -3px #888;
    }

JavaScript

day = new Date();
time = day.getTime();
day.setTime(time);
hour = day.getHours();
today = day.getDay();

    if  ((today >= 1) && (today <= 5))
        if ((hour >= 9) && (hour <=17))
            $('div#are-we-open')
                .addClass('open')
                .append('Good evening');
        else
            $('div#are-we-open')
                .addClass('closed')
                .append('We\'re Open! Give us a call!');
    else
        $('div#are-we-open')
                .addClass('closed')
                .append('We\'re Open! Give us a call!');

    if(hour === 0)
        $('span#insert-time').append('12 am');
    else if (hour === 1)
        $('span#insert-time').append('1 am');
    else if (hour === 2)
        $('span#insert-time').append('2 am');
    else if (hour === 3)
        $('span#insert-time').append('3 am');
    else if (hour === 4)
        $('span#insert-time').append('4 am');
    else if (hour === 5)
        $('span#insert-time').append('5 am');
    else if (hour === 6)
        $('span#insert-time').append('6 am');
    else if (hour === 7)
        $('span#insert-time').append('7 am');
    else if (hour === 8)
        $('span#insert-time').append('8 am');
    else if (hour === 9)
        $('span#insert-time').append('9 am');
    else if (hour === 10)
        $('span#insert-time').append('10 am');
    else if (hour === 11)
        $('span#insert-time').append('11 am');
    else if (hour === 12)
        $('span#insert-time').append('12 pm');
    else if (hour === 13)
        $('span#insert-time').append('1 pm');
    else if (hour === 14)
        $('span#insert-time').append('2 pm');
    else if (hour === 15)
        $('span#insert-time').append('3 pm');
    else if (hour === 16)
        $('span#insert-time').append('4 pm');
    else if (hour === 17)
        $('span#insert-time').append('5 pm');
    else if (hour === 18)
        $('span#insert-time').append('6 pm');
    else if (hour === 19)
        $('span#insert-time').append('7 pm');
   ...