The four tween days are the four days that mark the half way point between the Seasonal Stellar Days. The four tween days are: Imbolc the Herald of Spring (Mera 6, Horning 16), between spring and winter Beltaine, Spring Fertility Festival (Nami 16, Afterverdance 16), between spring and summer Midsummer's Night (Greymoria 16, Thrimlich 26), between summer and autumn Samhain (Hallisan 36, Blooding 16), between autumn and winter. Besides marking the passing of the seasons, the tween days are often considered lucky or auspicious or unlucky depending on how you look at it. Certain magical endeavors are easier and harder on this day. Many reagents work best when planted or harvested on a Tween Day. Tween days mark the halfway point between the seasons and this metaphysically makes these days well suited to forming other bridges. Bridges between nobles and commoners, bridges between the living and the dead, bridges between Fae Home and the material plane among many other things that are normally apart.