13 Moon Calendar



The word Calendar comes from the Latin “calendarium”, a name given to books utilized for tracking payments and recording time. The first day of each month was called by the Romans kalendae or calends, day when the debts were due. There are currently several calendars utilized worldwide, the Gregorian Calendar being the most commonly used.

All calendars refer to a cycle and the way of dividing the cycles themselves defers.

Gregorian Calendar

The Gregorian Calendar is a solar calendar of 365 days divided in 12 irregular months of 30-31 days each and February with 28 or 29 days (referring to a Leap year every 4 years, excluding centuries that cannot be divided by 4).

Pope Gregory XIII modified this calendar in 1582 as a reform to the previous Julian Calendar. When adding the month of July (by Julius Caesar) and August (Augustus Caesar), the sequence of names lost their meaning.

Let’s take a look:
September comes from Septem (seven in Latin) and it refers to our 9th month;
October from Octo (eight), our 10th month;
November from Novem (nine), our 11th month, and
December from Decem (ten), our 12th month…

Although we take this calendar for granted as a way to regulate and organize our society, in reality it doesn’t have any correlation to nature’s cycles and even the names are wrong!

13 Moon Calendar

One Year equals to 365 days, the time it takes the Earth to orbit around the Sun.

The cycle of the moon orbiting around the Earth is 28 days, an average of the synodic cycle (29.5 days between new moon to new moon) and the sidereal cycle (27.1 days until the moon reappears in the same place in the sky). 28 days also refers to the female biological cycle.

When dividing a Year cycle in Lunar cycles, we get: 365 days / 28 days = 13 moons + 1 day

In other words, the 13 Moon Calendar is based on 13 moons of 28 even days per solar cycle + 1 day of transition (13×28 = 364+1). The 28 days per moon are divided in 4 weeks of 7 days each, giving 52 even weeks per year.

The original 13 moons x 28 days cycle was also used by the Egyptians (Thoth), Druids, Polynesians, Incas, some Native Americans and the Chinese.

In the modern version, each moon of the 13 Moon Calendar has the name and characteristics of the 13 Lunar Tones in the Tzolkin. Each moon is also named after an animal, based on the 13 major constellations rediscovered by Hugh Harleston.

Beginning of the year – July 26

Every year, our Sun rises with the brightest star, Sirius, on July 26th. This is the day when the 13 Moon Calendar starts. It is believed that in this day our planet receives intense light and cosmic energy that accelerates our evolution.

Other ancient calendars that started on July 26 were the Mayan calendars Haab and Tun Uc “moon count” as well as the Thoth calendar of ancient Egypt.

The 13 Moon Calendar runs from July 26 to July 24 every year and, when combining it with the Tzolkin, the energy for this cycle relates to the Kin that falls on July 26.

Day out of Time – July 25

July 25 is known as the Day out of Time, representing a day of transition between the old and the new year.

It is also know as the Green Day, Day of Universal Forgiveness and Day of Purification. Since 1992, this day is annually celebrated as “Planetary Peace through Culture”, dedicated to ceremonies, artistic expressions and creativity. People get together all over the world to enjoy outdoor activities, listen to music and just share a special moment.

As July 25 does not belong to any moon or week in the 13 Moon Calendar, this day is an opportunity to truly experience timelessness, our freedom of being alive. We are invited to reflect, meditate, practice forgiveness, and prepare ourselves for the new cycle.

Leap years

The real duration of a solar year is around 365.25 days. In order to synchronize it with the astronomical and seasonal cycles, the Gregorian Calendar adds an additional day every 4 years, which means that every 4 years the length of the year is 366 days instead of 365. This additional day is added as February 29 and the 366-day year is called a Leap year. This norm excludes centuries that cannot be divided by 4.

The 13 Moon Calendar does not recognize February 29 as an extra day. Within the 13 Moon Calendar, this additional day is called 0.0.Hunab Ku, which repeats itself every 4 years between the 22nd and the 23rd days of the Galactic Moon and can be considered as an extra day out of time.

If you are interested in learning more about the 13 Moon Calendar, please visit You can get the 13 Moon calendar here and download it free on their website.

Dr. Jose Arguelles (1939-2011)

Dr. Jose Arguelles

Dr. Jose Arguelles (bio), founder of the Planet Art Network and the Foundation for the Law of Time, identified two time frequencies:

12:60 the “mechanized time”, where “Time is Money”, and
13:20 the “natural time”, where “Time is Art”.

While the 12:60 frequency is based on an artificial time, the irregular and illogical 12-month Gregorian Calendar combined with the 60-minute mechanical hour, the 13:20 frequency states that a calendar based on natural cycles becomes an instrument of synchronization.


“Just as air is the atmosphere of the body, So time is the atmosphere of the mind; If the time in which we live consists of uneven months and days regulated by mechanized minutes and hours, that is what becomes of our mind: a mechanized irregularity. Since everything follows from mind, it is no wonder that the atmosphere in which we live daily becomes more polluted, and the greatest complaint is: ‘I just don’t have enough time!’ ” ~ Arguelles