Do what thou wilt shall be the whole of the Law.

The Thelemic Calendar begins in 1904, the year in which Aleister Crowley received The Book of the Law and inaugurated the New Aeon of Horus.

When writing dates in the Thelemic style, Thelemites usually indicate the astrological positions of the Sun and Moon rather than refer to a month and day. The year is written as the number of years since the start of the New Aeon of Horus on March 20, 1904.

Furthermore, the Thelemic year is often written as a pair of numbers, such as IV:15. The first Roman numeral refers to the number of 22-year cycles since 1904. The second number refers to the number of years in the current cycle (0 through 21). Thus, the year IV:15 is (IV times 22) = 88 + 15 = Thelemic Year 103 (2007). Using this system, IV:0 is 1992, IV:1 is 1993, and so on. The letters "A.N." may be appended to the year, signifying "Aerae Novae" or "New Era" in Latin.

Writing the Thelemic year in this manner allows a correlation to be drawn between the year and the trumps of the Tarot, which are numbered from 0 through 21. Therefore, the year IV:5 may be seen as the year of the Hierophant (Card V) in the cycle of the Emperor (Card IV).

So, a complete Thelemic date (with common translation), might be written as:

Sun in Scorpio
Moon in Libra
Anno IV:15 A.N.
(November 5, 2007 e.v.)

When referring to dates in the Gregorian (common) calendar, Thelemites often follow the convention used by Aleister Crowley to distinguish them from the Thelemic calendar, which is to append the initials e.v. after the date. These stand for the Latin phrase "era vulgaris", which means "common era" and is equivalent to the modern designation "C.E." used in secular and scholarly contexts instead of "A.D."

The current Thelemic Date is: Sun in {ssign}, Moon in {lsign}, Anno V:{year2} A.N.

Thelemic Holidays

The following holidays are celebrated by Thelemites worldwide:

Equinox of the Gods (March 20)
The anniversary of the beginning of the Aeon of Horus in 1904 e.v.. This date also marks the beginning of the Thelemic New Year.
Three Days of the Writing of the Book of the Law (April 8, 9, 10)
Over these three days in April 1904 e.v., Aleister Crowley received the three chapters of The Book of the Law. These holidays are typically celebrated with readings of each chapter on its respective day.
First Night of the Prophet and his Bride (August 12)
On this day in 1903 e.v., Aleister Crowley was married to his first wife, Rose Kelly. Rose was to play an important part in the inauguration of the New Aeon and the reception of The Book of the Law.
"Crowleymas" (October 12)
The anniversary of Aleister Crowley’s birth in 1875 e.v..
Crowley’s "Greater Feast" (December 1)
A celebration to commemorate the death of Aleister Crowley on this day in 1947 e.v..
Equinoxes and Solstices (March, June, September, December)
The seasonal turning points of the year, traditionally celebrated by many cultures throughout history, are also ritually observed by Thelemites and other practitioners of Magick.

Love is the law, love under will.