From Longman Dictionary of Contemporary Englishhalcyon dayshalcyon daysliteraryHAPPY a time in the past when you were very happy → halcyon
Examples from the Corpus
halcyon days• The post-merger period amounted to halcyon days for Hook Harris.• Who, in its halcyon days, imagined Carthage a ballroom for the wind?• You're in a dreary barn of a place, its halcyon days long gone.• For a time the halcyon days of 1825 returned.• Hot, halcyon days of sunshine and vapour trails, butterflies and crammed picnic baskets.• He wrote and thanked the Lord Treasurer for restoring his halcyon days, showing his love for Halling.• It was from those halcyon days that the following story dates.• But the halcyon days were short-lived. 