Anyone that follows my blog realizes sooner or later that my monthly challenges don’t start the first day of a month and continue until the last day. This is true, but only if you are using the Gregorian calendar. In scheduling my challenges, I use a lunisolar calendar.

The popular Gregorian calendar is strictly a solar calendar. What this means is that it tracks the movement of the sun in its calculation of a year. However, it does not use the moon to determine the beginning of a month. It simply approximates month length and places 12 of them in a year. Since the moon revolves around the earth more than 12 times per year, the months don’t line up with moon phases.

A lunar month is approximately 29.5 days. Average months on the Gregorian calendar are 30.5 days. This means you will usually have one of the moon phases twice in the same month. We even have a term for this when it occurs with the full moon: a blue moon, as heard in the expression, “once in a blue moon!”

If you use the Gregorian calendar, anything involving the sun will stay the same year by year:

• Vernal equinox (start of spring) is always March 20
• Summer solstice (start of summer) is always June 20
• Autumnal equinox (start of fall) is always September 20
• Winter solstice (start of winter) is always December 20

Occasionally, these might vary by a day, since the Gregorian calendar is not actually the same length of time as it takes the earth to revolve around the sun. It is a bit shorter, which is why we need a leap year every four years. Actually, even this doesn’t quite sync the calendar and the earth’s yearly revolution, and so there are a few more corrections that are made.

According to the United States Naval Observatory,

Every year that is exactly divisible by four is a leap year, except for years that are exactly divisible by 100, but these centurial years are leap years if they are exactly divisible by 400. For example, the years 1700, 1800, and 1900 are not leap years, but the year 2000 is.

With those corrections in place, the Gregorian calendar charts the movement of the earth around the sun with precision and accuracy. This is extremely useful in establishing uniform dates across the globe. However, it downgrades months to just tick marks in a year, instead of them being grounded in their own astronomical movement.

This is what a lunisolar calendar tries to incorporate. The problem with a lunisolar calendar is that there aren’t the same amount of months in each year, which makes scheduling things more difficult (holidays for example). However, a lunisolar calendar makes months feel more significant since they are actually rooted in something real – namely, the phases of the moon.

It is for this reason that I use my own version of a lunisolar calendar when scheduling my monthly challenges, as well as for celebrating the new year. How does this calendar work? I am so glad you asked.

I follow a very basic rule in establishing the beginning of the year, the month, and the day: everything is birthed in darkness, reaches full luminosity half-way through, and ends in darkness. Here are the specifics:

• The beginning of the year – The year begins after the winter solstice, or the shortest day of the year (least amount of sunlight).
• The beginning of the month – The month begins after the astronomical new moon, or the moment of greatest darkness.
• The beginning of the day – The day begins at solar midnight, or the moment of time where my location on earth is exactly opposite -180 degrees away from – the sun.

That is basically it. The only slightly complicating factors are that the new year must start at the beginning of a month, and the beginning of each month must start at the beginning of a day. So, to figure out when New Years Day is (according to this calendar), here are the steps you take:

1. Look up when the Winter Solstice is. In 2022, it will occur on December 21st at 3:48 PM.
2. Determine the first new moon that falls after that time. This year, it will be December 23rd at 4:16 AM.
3. Find the next solar midnight after that time. In this case, it will be 12:20 AM on December 24th.

The other issue is the dateline, but I will leave a discussion of that for another time. I hope this clarifies some of my challenge scheduling and perhaps inspires you to better understand the way we mark times and seasons throughout the year.

Namaste.