Origin: The Halcyon is a bird of Greek legend and the name is now commonly given to the European Kingfisher. The ancients believed that the bird made a floating nest in the Aegean Sea and had the power to calm the waves while brooding her eggs. Fourteen days of calm weather were to be expected when the Halcyon was nesting – around the winter solstice, usually 21st or 22nd of December.
The Halcyon days are generally regarded as beginning on the 14th or 15th of December. Now, the saying connotes the beautiful sunny days of summer.
To find out the rest of the story, see: http://www.phrases.org.uk/meanings/halcyon-days.html
Energetically, Diane Tegarden