To understand how the Lukashian Calendar works, we have to start with the question of what a calendar actually is.

The most common answer is "a way to measure time", but since a calendar is based on the movements of a planet in the solar system, and those movements are not constant, this answer is not ideal.

A better answer is that a calendar is a way to model the movements of a planet in the solar system in a way that is useful to people on that planet.

By removing everything that has been made up by people over the millennia and simply looking at the actual movements of a planet in the solar system, we get a much more accurate, simple and truly global calendar mechanism. So, before you read on, clear your mind of everything you know...

On this page, we will have a look at how the Lukashian Calendar works on Planet Earth. Later, we will see how the mechanism is not specific to a particular planet and can seamlessly be applied to any planet.

On Earth, a year is defined as a solar Earth year, that runs from a southern solstice (inclusive) to the next southern solstice (exclusive), i.e. a single rotation of the Earth around the Sun, in terms of the cycle of the seasons. The first year is year 1 and years before year 1 are not defined. Southern solstice is a natural point in time for one year to end and the next year to start. Also, it almost coincides with the turn of the year in the Gregorian Calendar (southern solstice is usually around 21 or 22 December), which is a nice side effect to have.

A day is defined as a true (or apparent) solar Earth day, i.e. a single rotation of the Earth around its own axis, in terms of its angle towards the Sun. A day runs from its start (inclusive) to its end (exclusive). The first day of every year is day 1.

With these definitions, the durations of the years and days are not constant. Due to astronomical and planetary developments, the durations are variable: one day or year can be slightly longer or shorter than another. For example, the difference between the shortest and the longest day of the year can be more than 50 seconds (we're talking about full days here, not about daytime when it's light outside).

To see why this is the case, have a look at this video:

By embracing variable durations of days and years and designing the calendar around it, we no longer have to shoehorn a reality without constant durations into a calendar system with constant durations. This means no more leap seconds and leap days.

A simplified illustration of a few years and days, where we exaggerate the variable durations, is this:

In the real calendar, of course, the durations of years and days differ only a little.

We can see that the turn of a year generally does not coincide with the turn of a day. This makes perfect sense, because the rotation of the Earth around its own axis (which causes days) is completely independent of the rotation of the Earth around the Sun (which causes years). There is no reason why there should be a whole number of days in a year!

A day is part of the year that it starts in, even if it finishes in the next year. This automatically results in some years having one more day than others, making leap days unnecessary. This solves a fundamental problem of traditional calendars, which try to squeeze a whole number of days into a single year and then run into problems when things don't add up anymore.

A week is a period of 10 days. The first 7 are working days and the last 3 are weekend. This means that people have slightly more time off compared to the old calendar. Each day simply has a number, such as 1, 2, 3, all the way to 365, and sometimes 366. We don't need months and the days don't need names, like Monday or Tuesday. To know which day of the week it is, we simply look at the last digit. Is it an 8, 9 or 0? Then it's weekend!

The start of the Lukashian Calendar is called the Lukashian Epoch and is at the exact instant of a particular southern solstice. So, which southern solstice was chosen to be the first one? In other words: when does the Lukashian Calendar start?

Let's consider that years run from southern solstice to southern solstice, which follows from nature. Days correspond to one rotation of the Earth around its own axis, that follows from nature as well. But when to start counting, that does not follow from nature, that is for us to choose!

The southern solstice that was chosen to be the start of the Lukashian Calendar is the one 5925 years ago. This number was chosen for three reasons:

Before we state the third reason, let's examine the effect that the start of the calendar has on the point at which one day ends and the next day starts.

Here are some arbitrary southern solstices from the past that we could choose as the start of the calendar:

Choosing this southern solstice will lead to the following calendar:

The arrows point out the instants at which one day ends and the next day starts. What would happen if we choose a different southern solstice as the start of the calendar?

This would lead to the following situation, with the previous situation in grey, for comparison:

As we can see, the turn of day has shifted by a considerable amount of time! This is because the start of the calendar defines both when one year will end and the next year will start, as well as when one day will end and the next day will start. The first year and the first day start when the calendar starts, and as we've seen, the point at which the calendar starts, is the only thing that is for us to choose! After that, astronomy takes over and a day will be a rotation of the Earth around its own axis and a year will be a rotation around the Sun.

Considering this, when do we want one day to end and the next day to start? The Lukashian Calendar does not have time zones, so the point at which one day ends and the next day starts will be the same for everyone on the planet. A natural point for this to happen, would be when it's nighttime for the vast majority of the world's population. This is when the entire region from westernmost Europe/Africa to easternmost Asia/Australia faces away from the Sun.

So, if we have a natural point for a year to start and a natural point for a day to start, we must choose the start of the calendar in such a way that it coincides with both! And at the southern solstice 5925 years ago, the entire region mentioned above happened to face exactly away from the Sun!

So, by choosing that particular southern solstice as the start of the calendar, the last 2 digits of the year are mostly the same as the old calendar, all of human history fits and the vast majority of people on Earth will start their day in bed.

Since the duration of a day is not constant, we cannot use constant-duration units, like hours and minutes, for timekeeping. Therefore, the time of day is simply expressed as the proportion of the day that has passed. To achieve the desired scale, this proportion is represented in terms of basis points (beeps). This is simply a number that runs from 0 (inclusive) to 9999 (inclusive). The time of day is therefore expressed as, for example, 5628, when 56.28% of the day has passed.

The reference implementation of the Lukashian Calendar uses a millisecond resolution, so programmers can actually use a much higher precision than beeps when working with the time of day. Each individual millisecond on the timeline can be uniquely identified. For end users however, beeps provide the most useful representation.

The Lukashian Calendar does not have time zones, so it is the same time everywhere on the planet.

If you want to see how the mechanism of the Lukashian Calendar is not specific to Planet Earth, but can easily be applied to, for example, the upcoming Mars Settlement, then have a look here!

The internal mechanism of the Lukashian Calendar knows the exact durations of all the years and all the days in milliseconds and the offset between the Lukashian Epoch and the UNIX Epoch. This offset marks the start of the calendar.

All durations are defined in terms of Terrestrial Time. This means that, unlike the Gregorian Calendar, days in the past are not defined in terms of how the second was defined back then.

For calculating the durations, the Lukashian Calendar uses the Equation of Time, the Tidal Deceleration formula and solstice algorithms by Jean Meeus.

The Lukashian Calendar also provides a mechanism for loading the durations from an external resource, so that the official durations of days and years can be centrally maintained and governed.

If you want to play around with the Lukashian Calendar Mechanism, then you can download it here!