The first brief in an appeal to a case that struck down Utah's gay marriage ban is due by January 27.

In 2004, 65.8 percent of voters approved Amendment 3, which prohibits the state from recognizing any union other than a heterosexual marriage.

U.S. District Court Judge Robert Shelby earlier this month declared the amendment invalid, which led to a rush of gay and lesbian couples marrying in Utah.

(Related: More than 900 gay couples tie the knot in Utah.)

Utah officials appealed the ruling to the 10th Circuit Court of Appeals in Denver, which on Monday ordered the state to file its opening brief by January 27. Plaintiffs, 3 gay couples, have until February 18 to file a response. The state must file any reply by February 25.

“Requests for extension of time are very strongly discouraged and will be considered only under extraordinary circumstances,” the court wrote.

The compressed timetable could result in a resolution to the appeal by late spring and could complicate the state's pending request for a stay before the U.S. Supreme Court.

(Related: Utah could ask Supreme Court to review gay marriage ruling.)

“What's another two months when anybody who wanted to get married immediately probably already did anyway?” appellate attorney Troy Booher told Deseret News.