So for example, I was born on December 13, 1959. The winter solstice immediately preceding my birthday would be December 21, 1958 (in the Northern hemisphere, since that’s where I was born). So counting up from December 22, 1958 (first day of Birch Moon for that year), in 28 day increments, we arrive at the 13th month, or Elder Moon.
Since we use months of 28 days as a matter of convenience, our months don’t line up perfectly with the lunar cycle, but they’re close enough for our purposes. With 13 months of 28 days each, we have a total of 364 days. The leftover day (marking our ‘year and a day’ period) is a holy day dedicated to Mistletoe. In leap years, we have two days dedicated to Mistletoe. If you are born on a Mistletoe Day, you have the potential to be a powerful healer.
Of course, in the Southern Hemisphere, the winter solstice falls on or around June 20-21, so the day after June 20 would be the first day of Birch Moon in the Southern Hemisphere. The months would be reversed south of the equator. The High Days would also be reversed.
For our folks in the Southern Hemisphere, here’s a chart to tell you which High Day you’d be celebrating relative to the Northern Hemisphere.