JSFiddle - React, Tailwind, and code Playground

HTML

<ul id="asset-list" class="expandable selectable normal" style="height: 671px;">
    <li class="selected">
        <div class="thumb"> <a href="/content/assets/750"><img src="https://www.google.com/images/srpr/logo11w.png"></a>

        </div>
        <div class="title">
            <div> <strong>Title of story</strong>

                <br> <span class="on-air-date">
      On air: 10/28/14 05:30:00pm
       [750]
    </span>

                <br> <span class="blue radius label">Staging</span>
 <span class="green radius label">Live</span>

            </div>
        </div>
    </li>
    <li>
        <div class="thumb"> <a href="/content/assets/4200"><img src="https://www.google.com/images/srpr/logo11w.png"></a>

        </div>
        <div class="title">
            <div> <strong>Another story title</strong>

                <br> <span class="on-air-date">
      On air: 12/10/14 02:09:18pm
       [4200]
    </span>

                <br> <span class="blue radius label">type label</span>

            </div>
        </div>
    </li>
    <li>
        <div class="thumb"> <a href="/content/assets/4201"><img src="https://www.google.com/images/srpr/logo11w.png"></a>

        </div>
        <div class="title">
            <div> <strong>Yet another story title</strong>

                <br> <span class="on-air-date">
      On air: 12/10/14 02:09:18pm
       [4201]
    </span>

                <br> <span class="blue radius label">type label</span>

            </div>
        </div>
    </li>
</ul>

CSS

li {
    list-style-type: none;
    padding-top: 10px;
}
.thumb, img {
    height: 90px;
    width: 200px;
}

JavaScript

function returnAirDate () {
    $(".on-air-date").each(function(index,value) {
        var str = $(value).text();
        console.log(str.match(/\[(.*?)\]/g)[0].replace(/\]/g,'').substring(1,str.length-1));
    });
    
}

returnAirDate();