JSFiddle - React, Tailwind, and code Playground

HTML

<div class="timeline march eventCal">
    <div class="tm-body">
       <div class="tm-title">
          <h3 class="h5 text-uppercase curMonth">March 2015</h3>
        </div>
          <ol class="tm-items">
            <li></li>                               
          </ol>
        <div class="tm-title">
          <h3 class="h5 text-uppercase nextMonth">April 2015</h3>
        </div>
      </div>
</div>

JavaScript

var currentMonth = $('.curMonth').text();
 var currentSplit = currentMonth.split(" ");
 var curMonth = currentSplit[0].toLowerCase();

// find current month and hide div
        $('.' + curMonth).removeClass('eventCal')
        .find('.tm-title:first h3')
            .removeClass('curMonth')
            .closest('div')
            .next('.tm-title h3')
            .removeClass('nextMonth');

        // show next month
        $('.' + nexMonth).addClass('eventCal');