The Celtic calendar consists of thirteen months based on the lunar cycle. The holiday called Samhain marks the end of the year. It is celebrated from sunset on October 31st until sunset on November first.
This time was chosen because it was the midpoint between the autumn equinox and the winter solstice, and so this Gaelic festival marks the end of the harvest season and the beginning of winter or the “darker half” of the year.
An interesting feature of this lunar calendar is that after Samhain there is a period of five days that are not a part of the calendar year. This is a time considered to be between the states of chaos and change. It is a transition between the old and new year. It is a period of “no-time” and we enter that period tonight.
After we pass through these transitional five days of “no-time,” the new year begins.
Of course, a lunar calendar isn’t as accurate as our modern calendar, but in its time it served the needs of people. The no-time was a way to adjust the lunar calendar to make a year that coincided with astronomical events.
Afte the period of no-time, a short first month of Maghieden launches the year. It is considered an auspicious time for births, beginnings and a good time to start a journey. Maghieden lasts until the next full moon making it the shortest month of the year.
In this kind of lunar calendar the “Full Moon” marks a period of time rather than an event on one night. It would be as if when the Full Moon came next for us we called it the November Moon and started the month on that day and it lasted until the December Full Moon.