Here is a recent article by David Halpin, a colleague of mine who writes extensively, and excellently about esoteric subject matter, including the faeries. It is published on the Ancient Origins website, where he is a guest author.
“… the realm of fairy or the crypto-terrestrial is more often encountered through places considered sacred or having an alignment of some kind in relation to auspicious days in the yearly cycle, such as solstices, equinoxes and new moons. In many legends passed down from oral traditions the liminal moments at dusk, between sunset and moonrise, are when the ethereal forms of these beings are best seen.”
It’s a top-notch read… here is the link: Mysterious Worlds: Travels to the Faerie and Shamanic Realms by David Halpin