trial court initially held that civil unions, in contrast with same-sex marriages, were
       not against public policy in Illinois. The court then held that the parties’ Vermont civil union
       was valid as of July 20, 2002, the date on which it was entered into. The court declared the
       Canadian marriage null and void, because it was a second civil union entered into while the
       Vermont civil union was valid. Finally, the court held that the parties had satisfied the statutory
       grounds of irreconcilable differences.
¶ 23        The court proceeded to consider theRespondent argues that recognizing their civil union as commencing in 2002 means that
       we are giving retroactive application to the Act. We disagree. As we have determined, the Act
       operates only as of its effective date. Thus, it is prospective. However, the Act may operate
       upon antecedent facts, such as the fact that a civil union was entered into before the Act’s
       effective date. Here, the original petition for dissolution of the civil union was filed in August
       2011, after the effective date of the Act. There is no question that the Act was effective as of
 