Markup: templates/output/04-elements/forms/input/datetime.html
<form class="powermail_form" action="#" method="post">
<div class="powermail_fields">
<div class="powermail_fieldwrap powermail_fieldwrap_type_input">
<label class="powermail_label" for="demoformid-idt">Birthday (date and time)
</label>
<div class="powermail_field">
<input class="" type="datetime" name="" id="demoformid-idt" value="1970-01-01T00:00:00Z"/>
</div>
</div>
<div class="powermail_fieldwrap powermail_fieldwrap_type_input">
<label class="powermail_label" for="demoformid-idt-error">Birthday (date and time)
</label>
<div class="powermail_field">
<input class=" powermail_field_error" type="datetime" name="" id="demoformid-idt-error" value="1970-01-01T00:00:00Z"/>
<ul class="powermail-errors-list filled" aria-live="polite">
<li>This field is required</li>
</ul>
</div>
</div>
</div>
</form>
Source:
assets/sass/04-elements/_elements.forms.scss, line 190