It happens I have invented a holiday - a midwinter one, even- and I wrote a novella around it for AMID THE WINTER SNOW. That anthology, a wonderful collection of midwinter holiday fantasy romance novellas, is sadly no longer available.
BUT, you can read my story, THE SNOWS OF WINDROVEN, in either digital or print formats. Despite the fierce cover, this is a story about second chances, and the renewal of hope that the midwinter holidays bring, drawing light out of darkness.
I hadn't really set out to create a midwinter holiday, necessarily, but when I wrote my original Twelve Kingdoms trilogy, I created a mythology with three goddesses. And where you have goddesses, you have followers - and feast days! In this world, Moranu is the goddess of night, of the moon, of shadows, magic, and changeability. So, of course, her feast day occurs at the winter solstice.
Here's a bit from THE SNOWS OF WINDROVEN describing the holiday.
***
Just before the clock struck midnight,
Ami and I threw our dark secrets into the fire. She’d never done that part of
the tradition, but enthusiastically embraced it. She and I spent the last dark
hours of that year writing down all the things we wanted to leave behind.
Holding hands, we burned them, consigning them to ash.
Then we collected the sleepy twins and took our votives to
the big landing, where everyone had assembled. Graves and Skunk were there, and
many other people I’d never seen before. All in their best finery. Even the
lowest servants joined us, dousing the last of the castle lights as they did,
standing on the ascending stairways if they couldn’t crowd onto the landing. At
the chime, we blew out the last of our candles, standing together in the dark.
Beyond the great glass windows, the sparkling dark night resolved.
The second chime rang, and people began to relight their
candles. I lit Stella’s, her luminous eyes catlike and solemn, while Ami lit
Astar’s. Outside the windows, torches lit at the castle walls, then ran in a
rapidly expanding circuit around all the turrets, then pouring down the winding
road down the peak. Ami laughed with pure joy and the kids squealed, nearly
forgetting their own candles.
“I so hoped the wind would stop long enough for this,” Ami
told me. “I really wanted to see it. For all of us.”
“I understand why,” I told her, cupping her cheek. In the
brilliance of the moment, I didn’t care who watched us. I kissed her, something
rekindling inside me also, the light spreading throughout.