`Happiness," as somebody once said, "is never experienced, only remembered." Thus it is that the term "halcyon days" is often used to recall a happy care-free time, a period long since gone of youth, prosperity and peace.
The original halcyon days, however, were specific, and represented a concept similar to that of the medieval St Martin's summer, or our own Indian summer. They comprised a brief period of unseasonably sunny, mild and nearly windless conditions in the Mediterranean that seemed to turn up with remarkable regularity around the winter solstice.
The fine spell could last anything from two days to a few weeks, but was very often of about 14 days duration.
The traditional explanation for the name is that the ancient Greeks connected the spell of good weather to the halkyon, a bird which has been confidently identified from various classical references as Alcedoatthis, a species of kingfisher.
The story was that the halkyon took advantage of the good weather to build its nest and hatch its eggs around this time of year - usually, we were told, from seven days before the solstice to seven days after it.
Noticing that this brief domestic urge seemed to coincide so regularly with the fine weather spell, the Greeks called the period "halcyon days". Today, December 11th, was regarded as marking the beginning of these original halcyon days, when the Greeks could expect a brief meteorological interlude of quiet in an otherwise somewhat turbulent world.
This theory, however, has one potentially fatal flaw. Dr Pat Cronin of the Department of Ancient Classics at UCC has pointed out that the Alcedoatthis does not nest during wintertime at all, but Dr Cronin has provided an alternative and plausible explanation for the term "halcyon days".
The brightest star of the Pleiades, or Seven Sisters, was known to the ancient Greeks as Hal kyon, and indeed the stars of the cluster as a group were called the Halkyons. The Greeks may have noticed that around this time of year, the Pleiades culminate at evening time - they occupy their highest position in the sky.
It may well have seemed to them that from this dominant position in the heavens, the Pleiades might be responsible for any coinciding peculiarities of weather. Dr Cronin suggests, therefore, that the halcyon days were named, not after the bird as traditionally thought, but from the stars.
Either way, these halcyon days, like our own, do not last long. As Virgil puts it, describing the return of winter, and the rising wind:
The flimsy gossamer now flits no more,
Nor halcyons bask on the short, sunny shore.