Halcyon

First of all, it is an African bird. Before that, it was the Greek myth of Alcyone, who was about to throw herself into the water to commit suicide when she learned about the death of her husband. The gods turned both of them into halcyons (the bird). Her father, the god of the wind, would make the wind calm for 7 days in the winter so that she could lay her eggs in a nest on the water. The halcyon days, then, are the calm days.

From the Oxford English Dictionary:

1390 GOWER Conf. II. 106 (Bodl. MS. 294) Hir briddes it..Of Alceon e name bere. 1398 TREVISA Barth. De P.R. XIX. lxxix. (1495) 910 In the cliffe of a ponde of Occean, Alicion, a see foule, in wynter maketh her neste and layeth egges in vii dayes and sittyth on brood..seuen dayes. 1545 JOYE Exp. Dan. Ep. Ded. (R.), Thei saye, that in the..coldest tyme of the yere, these halcions (making their nestis in the sea rockis or sandis) wille sitte their egges and hatche forth their chickens. c1592 MARLOWE Jew of Malta I. i, How stands the wind? Into what corner peers my halcyon's bill? a1631 DRAYTON Noah's Flood (R.), There came the halcyon, whom the sea obeys, When she her nest upon the water lays. c1750 SHENSTONE Elegies v. 22 So smiles the surface of the treach'rous main As o'er its waves the peaceful halcyons play. 1819 J. H. WIFFEN Aonian Hours (1820) 104 The brilliant halcyons..fluttering upon azure wings, appear Loveliest above secluded waters. 1867 Contemp. Rev. VI. 252 The alcyon sits her floating nest.
fig. a1649 DRUMMOND OF HAWTHORNDEN Poems Wks. (1711) 39/1 Makes Scotland's name to fly On halcyons wings..Beyond the ocean to Columbus shores. 1880 GOLDW. SMITH in Atlantic Monthly No. 268. 200 The halcyons of literature, art, and science were floating on the calm and sunlit sea.


My favorite is Alan Paton's use of "halcyon days" in Kontakion For You Departed, a memoir upon the death of his wife: "The halcyon days. I write of them with unbelievable longing to have again what one cannot have again, so that my desire to relive what cannot be relived begins actually to war against my knowledge, final and ineluctable, that it cannot be done. ... The halcyon days. And that means not only the sweetest days of life, it means also the days that cannot be lived again, except in memory."


The idea of a time of peace in the winter for the birth of a baby is strangely reminiscent of the birth of Christ and even of the Pax Romana (okay, I don't know if Christ was born in the winter).