Setting a date field via entitity_metadata_wrapper
I was able to get this to work in a roundabout way. I may have been able to accomplish the same thing with time(), but this read better for me as I could follow exactly what I was doing if I ever came back to the code in the future.

// Update the Acceptance Date of Current Agreement.
$acceptance_date = new DateTime(date('Y-m-d 00:00:00'));
$company_wrapper-&gt;field_acceptance_date-&gt;set($acceptance_date-&gt;getTimestamp());