Is it possible to change a format based on date?

For example all records with a date older than today have one value and all records with a newer date than today have a different value?

Why doesn't this work?

<span class="{{Employer_CallBack.where( &quot;Employer_CallBack&quot;, &quot;&lt;=&quot;, &quot;now&quot; ).then( &quot;yellowText&quot;, &quot;greenText&quot; )}}">{{Employer_CallBack}}</span>

Should show yellow text of date is today or past and green text if the date is in the future.