A Gift of Time by Jaclyn Osborn

Be careful what you wish for… it just might come true. Jack Taylor learns this the hard way. He’s a workaholic who wants that highly sought after corner office at the advertising agency he works for, and he’ll do anything to get it—even if that means constantly disappointing his fiance, Caden.
On his way home one Christmas Eve night, he’s dreading the argument he knows will happen once he walks through the door. To make matters worse, he forgot to get a gift for Caden, so he makes a quick stop at a Christmas shop he’s never seen before. Inside, he meets a mysterious man who sells him an antique clock. When he gets home, he and Caden fight, just as he expected, and he ends up sleeping on the couch.
Fuming from their fight, Jack makes a wish to have never met Caden. And it comes true.
Waking up in an alternate reality around Christmas, Jack has everything he’s ever wanted: the perfect job, fancy car, and luxurious apartment. But he soon realizes it means nothing without the man he loves.
There’s only one way to reverse the wish: get Caden to fall in love with him before Christmas Eve… or lose him forever.