Halcyon Days
Halcyon days originally named a specific fourteen-day calm spell around the winter solstice — now, loosely, any remembered period of peace.
Full definition of Halcyon Days →:: COMPARE ::
Halcyon daysvsIndian summer
The short answer
Both name a specific out-of-season calm spell tied to a calendar position, and both have drifted into loose figurative use. Halcyon days sits at the winter solstice; Indian summer is a warm spell in autumn. The drift in both cases lost the dates.
Side by side
| Aspect | Halcyon days | Indian summer |
|---|---|---|
| Season | Winter solstice | Autumn |
| Original length | 14 days | Variable |
| Names | Calm sea | Warm spell |
| Now used for | Nostalgia | Late warmth |
What each one means
Indian summer
The contrast above sets out how Indian summer differs from Halcyon Days on the points that actually matter.