public void setValidFrom(java.util.Date validFrom) {
        this.validFrom = validFrom;
    }
<p>
The starting date-time from which the certificate is valid.
</p>
<p>
Example: <code>2019-07-31T17:57:09Z</code>
</p>

@param validFrom
       The starting date-time from which the certificate is valid.</p>
       <p>
       Example: <code>2019-07-31T17:57:09Z</code>
aws-java-sdk-docdb/src/main/java/com/amazonaws/services/docdb/model/Certificate.java