The Pagan Book of Days: A Guide to the Festivals, Traditions, and Sacred Days of the Year, by Nigel Pennick (TPB, 1992, $2)
"The Pagan Book of Days lists sacred days of the natural year from the ... the Anglo-Saxon, Norse, Celtic, and Northern traditions- as well as some from Pagan Greece and Rome." If you are curious, you can read about the festivals and holy days of the pagan religions.
Look for this book in the new age religion section, avail. 11/2. (The placement is odd, since these festivals and holy days are anything but "new".)