As an idea, you could consider to use HTML5 elements in order to make it more semantic.

    <dl>
      <dt><time>2018-07-07 14:54:39</time> - <time>2018-07-07 17:12:05</time></dt>
      <dd>Did this and that</dd>
    </dl>

Native support for time ranges (e.g. through ISO8601 or a <range> element) might be coming soon in the HTML spec. Durations are already supported.