Analysis of information sources in references of the Wikipedia article "Wheel of the Year" in English language version.
The pre-Christian observance obviously influenced the Christian celebration of All Hallows' Eve, just as the Taoist festival affected the newer Buddhist Ullambana festival. Although the Christian version of All Saints' and All Souls' Days came to emphasise prayers for the dead, visits to graves, and the role of the living assuring the safe passage to heaven of their departed loved ones, older notions never disappeared.
Time out of time', when the barriers between this world and the next were down, the dead returned from the grave, and gods and strangers from the underworld walked abroad was a twice- yearly reality, on dates Christianised as All Hallows' Eve and All Hallows' Day.