Yule is a holiday celebrated in the midwinter in the Shire.
Yule consisted of two days called 1 Yule and 2 Yule. The last day of the year was 1 Yule and the first day of the next year was 2 Yule. The Yuledays fell between the months called Foreyule and Afteryule and were not part of either month. 1 Yule was always on a Friday and 2 Yule fell on Saturday.
Yule was one of the two chief holidays in the Shire the other being the midsummer holiday called Lithe. The Yule celebrations lasted six days in total, including two days before and two days after the Yuledays. This six-day period was called Yuletide. It was a time of feasting and merriment.
After the War of the Ring, it was feared that the Yule feasts would be rather meager due to shortages of provisions in the Shire. But large stores of food and beer were found in the tunnels of Michel Delving and in the quarries at Scary and in other places, so the Yuledays were a time of great cheer.
The Elves did not have a celebration at midwinter. It appears that the Rohirrim maintained the custom of celebrating the midwinter holiday as their ancestors the Northmen had done. The name of the holiday in Rohan is not known but it was most likely similar to "Yule."