Today’s decision from the Sixth Circuit, the only federal appellate court opinion so far rejecting constitutional claims for same-sex marriage, has two obvious consequences.

The first is that just a month after the Supreme Court had seemingly dodged the issue for the rest of its 2014 Term, Judge Jeffrey Sutton’s decision in DeBoer v. Snyder has brought it back for resolution, likely as early as June 2015 or as late as June 2016.

The second consequence is that the Sixth Circuit decision ensures the Justices will have before them at least one well-written and reasoned opinion against constitutionalizing the issue of same-sex marriage. After dutifully arguing for four pages that he was bound by the ancient one-line decision from the Supreme Court in Baker v. Nelson, Judge Sutton nevertheless used the next 25 pages of his opinion to address the merits. He was right to do so. And he was right to focus on the many post-1972 changes in doctrine that might affect the outcome.

In this post, I’ll look at the possible timing of a Supreme Court decision on same-sex marriage.  In a future post or posts, I’ll offer some reactions to the substance of Sutton’s opinion, which addresses the major arguments for same-sex marriage resting on due process and equal protection (including rational-basis review, fundamental rights, heightened scrutiny of anti-gay discrimination, and animus).

The Supreme Court is capable of many surprises, some of them dispensed with a taciturnity only Calvin Coolidge could rival, but it’s now fairly safe to say that the Court will decide the merits of same-sex marriage no later than June 2016. In fact, I think it will probably be much sooner. Here’s why.

At least initially, timing is in the hands of the lawyers who argued for same-sex marriage before the Sixth Circuit. The lawyers from the four states (Michigan, Ohio, Tennessee, and Kentucky) could try to delay resolution in the Supreme Court by requesting en banc review from the Sixth Circuit. That could add months to the calendar, pushing off an eventual Supreme Court decision to the 2015 Term beginning next October. That would result in a decision likely no later than June 2016.

But in the meantime, one or more of the cases from the Fifth, Eleventh, Eighth, or First Circuits could be decided. The Fifth Circuit has set argument for the week of January 5, 2015. A decision from that court could come as early as February.

I assume each set of lawyers in the Sixth Circuit wants its case to be the one decided by the Court. And I take them at their word that their clients want an expeditious resolution of the issue. For the same-sex couples and their children in these cases, marriage is not some abstract cause. Even if some of the lawyers wanted to wait, I doubt all of them would. And it would take just one set of plaintiffs to file a cert petition that the Supreme Court could grant. The ACLU, which represents the Ohio plaintiffs, has already promised to seek Supreme Court review “right away.” On the other hand, if one set of plaintiffs did decide to seek en banc review, the Supreme Court might hold off accepting the case until the Sixth Circuit made a decision.

Beyond the personal interests in expeditious resolution, trying to delay a final decision until 2016 at this point would make little strategic sense. The Sixth Circuit, dominated by Republican-appointed judges, is not thought to be very hospitable to same-sex marriage claims. (The Sixth Circuit could even take the issue en banc on its own initiative.) So the outcome of an en banc review would probably be to affirm the panel, which would take the matter right back to the Supreme Court (if one of the cases from the other circuits, which include some fairly conservative courts, doesn’t get there first).

Petitions filed now don’t guarantee a decision during the current Term, of course. Ultimately, the Supreme Court’s decisionmaking schedule is in its own control. The Justices could receive petitions now and hold them over until next Term. Considering Justice Ginsburg’s view as expressed in September at the University of Minnesota Law School that a circuit split on same-sex marriage would create “urgency” on the issue, I don’t expect the Justices would do that.

To the extent that same-sex marriage advocates believe there are already five votes at the Supreme Court for same-sex marriage (a view shared by astute Court-watchers on both sides, including NRO’s Ed Whelan), any delay only raises the risk that there will be an unfavorable change in the Court’s composition. In light of Tuesday’s election result in the Senate, there can be no certainty that a favorable Justice would be replaced by an equally favorable one in the next couple of years. The seat could remain vacant, meaning a 4-4 split at the Court (which would affirm the adverse lower court ruling) and perhaps mean a re-argument after 2016 when the Court returned to full strength. Nobody can know what the 2016 election holds. Why risk it?

If same-sex marriage advocates file petitions immediately in the Court, the Justices could accept the case quickly, set a briefing schedule to be completed by, say, February, hold oral argument in March or April, and issue a decision this Term. If the Court holds to its practice of waiting until the end of the Term to decide momentous cases–and this would be the most momentous this year–that could mean a decision in May or June. All of the major gay-rights decisions so far–all written by Justice Kennedy, I might add–have been issued late in the Court’s session.  Romer v. Evans came down in May 1996. Lawrence v. Texas was issued on the last day of the session in June 2003. And United States v. Windsor was announced on the last day of the Term in June 2013.

This year, decisions will be issued on Monday, June 22, and Thursday, June 25, 2015. And then there’s one last possible decision day.  It’s not much more than a hunch, and it’s subject to about a thousand different contingencies, but you might want to plan on tuning in to your favorite 24-hour news channel at 10 a.m. (EDT) on Monday, June 29, 2015.