public void setEffectiveDate(java.util.Date effectiveDate) {
        this.effectiveDate = effectiveDate;
    }
<p>
The time for the modification to become effective.
</p>

@param effectiveDate
       The time for the modification to become effective.
aws-java-sdk-ec2/src/main/java/com/amazonaws/services/ec2/model/ReservedInstancesModification.java