Calendar

Day-of-year/solar cycle

The dates on this website are based upon the solar calendar. This means that the events listed on this page lack a great number of other cultural dates. This is because many cultures have historically kept time with a lunar or lunisolar calendar, following the phases of the moon. Lunar calendars are ~354 days long and therefore have the property of oscillating or drifting relative to dates on the solar calendar.

A primary reason for the preference toward the solar calendar is that it's more aligned with the seasonal changes of the earth.^[1]

What's wrong with the calendar?

The Gregorian calendar has numerous benefits. These benefits mostly correspond with fitting multiple systems into one system such that we are able to have a sensible idea of when various cultural touchstones are.

• The 365 day year follows the solar year in length, but January 1st does not corresponds to any meaningful astronomical position. It is rather arbitrarily placed due to being the date that Roman consuls took office.
• The 30-day month follows the lunar cycle. But in the Gregorian calendar the length of a month is somewhat random.

  Jan	31	Mar	31	Aug	31
  Feb	2829	Apr	30	Sep	30
  		May	31	Oct	31
  		Jun	30	Nov	30
  		Jul	31	Dec	31

  There is a reasonable symmetry to the last ten months, where both five-month blocks contain the same sequence of days. However most people do not ever notice this. Nor do they ever notice that "September", "October", and so forth take their names from numerals seven (septem), eight (octo), nine (novem). Despite this, September is the tenth month, not the seventh.
• The seven day week has numerous influences from ancient astronomy to religion to culture. Very simply, seven does not divide either the lengths of months or the number of days in the year, with the exception of February. This makes even less sense due to February being inconsistent with all other months.

Both the Gregorian and lunar calendars are best suited for day-to-day activities, in particular when these activities are meant to be done on certain days at regular, but short, intervals. This includes bills, work days, meetings, and other things that work against our psychological well being.

Aligning perception to a longer time interval encourages long term thinking. The solar cycle is the basic time unit we use to measure the span of our lives. It gives a simpler, one-variable mapping from:

whereas the Gregorian calendar is a two-variable mapping:

The day-of-year calendar is used widely when ambiguity must be avoided in physics, agriculture, climate science, and more.

Beginning and end

The calendar on this page begins a new year on the Winter Solstice. A leap day occurs with the same regularity, with the exception that a leap year adds one extra day to the end of the year rather than arbitrarily at the end of the second month of the Gregorian calendar.

The starting year of this calendar is 8,000 BC. While still arbitrary it is perhaps more meaningful to the history of humanity than the life of Jesus Christ. This date is less known as After the Development of Agriculture (ADA). A more well known variation is the Holocene calendar (HE) which begins on 10,000 BC.

The Warren Field calendar is thought to be the oldest timekeeping technology found so far. It is dated to ~8,000 BC.^[2]

This corresponds "close enough" to when durable civilizations began to become more common due to sustained agricultural efforts. It is a reasonable place to mark when keeping time with some precision started to become more important. It can also be "close enough" to the beginning of the Holocene and the end of the last interglacial period.

Therefore one can just add 8,000 to the Gregorian year to find the year of the calendar described on this website and on this page.

1. Historically there have been claims associating the lunar cycle to natural cycles and activities like farming. These beliefs do not appear to be empirically supported. _⤴
2. V. Gaffney, 2013 "Time and a Place: A luni-solar 'time-reckoner' from 8th millennium BC Scotland, Internet Archaeology" 34. doi.org/10.11141/ia.34.1 _⤴