How to build a better reform calendar for calendar reform.
Taking the Days from New Moon to New Moon as a given, this follows the steps in creating a civil calendar for as many of the world’s peoples as possible.
First, a visual representation of the relative amount of daylight. This applies to those North of the Tropic of Cancer and South of the Tropic of Capricorn. Those in the Tropics don’t see much change in daylight.
The amount of daylight varies according to the time of year. The closer to the poles, the longer the extremes of the length day and night become.
The following images use small circles to denote the days of the year by daylight at 49 degrees North. The circles are shaded according to the amount of daylight and night. The Winter Solstice, the longest night, is 100% black, the SUmmer Solstice 100% white and the rest shaded accordingly.

365 Days of the Year, in a circle to represent the Year and the Earth’s orbit around the sun. The darkest days are at the bottom, the lightest at the top.
With this as a starting point, we can organise the days in any manner we feel appropriate.

The image above represents the Gregorian Calendar, with January 1st at the bottom left, then continuing clockwise.
To address the irregularity in the calendar’s months and weeks, several reform proposals have found light. To create the best calendar for the world, let’s begin again with the circle of days.
The following circles use 364 days (because 52 weeks = 364 days, and the extra day isn’t a weekday)

The year divided into equal quarters of 91 days or 13 weeks. The quarters fall on or about one of the cardinal points: the Winter Solstice, the Vernal Equinox, the Summer Solstice, the Autumnal Equinox.
The Gregorian’s quarters have 90/91, 91, 92, 92 days.

midway through each 91 day quarter is a central day, with 45 days on either side of it. The diagonal lines join the 4 midway days of each Quarter. These denote the changes of season. The lowest arc is the time of the long nights and darkness. Proceeding clockwise, the left~hand arc is the time of the waxing days, and rising. The topmost arc is the time of long days and light. The fourth arc along the right stands for the season of waning days or waxing nights, or long shadows, and it descends, once again, to the Season of Darkness.
These attributes: day and night, rising and falling reintroduces light and gravity into our calendar. The amount of relative daylight according to the season, as well as the amount of light reflected by the Moon and other planets. Gravity defines time as much as light does.
If we take these 364 days, create 52 weeks, each Quarter is 13 Weeks long. It also allows for 13 Months of 4 Weeks or 28 Days.

The Days of the Year arranged as 13 Months of 4 Weeks apiece at 49N Latitude. Begin on the Winter Solstice at the bottom, and move clockwise around the circle. This has a symmetrical structure lacking in the Gregorian, and a number of other world calendars.

the Days of the Year arranged by 13 Months of 4 Weeks at 49S Latitude. Begin on the Summer Solstice at the top, and move counterclockwise around the circle.
Imagine the Year as a circle of Days, but with a gap at one end. The gap connects the circle at the end of one Year with the beginning of the next. This creates a spiral of successive years. The Clockwise Northern hemishpere and counterclockwise Southern hemisphere, together, form a double helix of these circles of Days.
Now we have 13 Months arranged according to daylight, which brings our Calendar Year in line with the Seasonal Year.
Although this doesn’t really apply to the people who live in the Tropics in terms of daylight, they live under the path of the Sun, and so celebrate two Days a Year when the Sun is directly overhead.

This Calendar component, which has no name but we have taken to calling tzolkin, provides an organizing principle to the 52 Week structure described above. The tzolkin has two coincident cycles, the numbers 1 to 13, and twenty glyphs (here represented by the roman numerals I to XX). Begin from the top left and move downward, column to column. Read the Days as 1~I, 2~II, 3~III and so on…
This 260~Day calendar tracks the number of Days it takes humans to gestate (266 Days over 9 Months from Full Moon to Full Moon). This represents our development physically, and our perception of light, sound and time.
If this Calendar is overlaid over the 365 Days of the Year, assigning a number~glyph to each of these Days, it creates another series of progressions.
from Day~to~Day, the number~glyph increase by 1~I. From Year~to~Year for any given Day, the number~glyph increase by 1~V.
For example, if today happens to be 9~VI then tomorrow will be 10~VII, the next day 11~VIII and so on. If today happens to be 9~VI, next Year on this Day will be 10~XI, the next Year 11~XVI, the next 12~I and so on.
The number~glyph on the last Day of any given Year is assigned to the New Year. Thus, if the last Day of of one Year falls on 9~XIX, then the New Year becomes Year 9~IV. This represents the notion that the present and future have seeds in the past.
Thus, the last day of the Year cycles through the glyphs IV, IX, XIV, XIX, the New Year Day that is not a weekday falls on V, X, XV, XX, and the first Day of the Year falls on I, VI, XI, XVI.
This interrelation between the 52~Week Year and the 260~Day Calendar creates a cycle of 52 Years, where the Days of the Week and Month and number~glyphs begin to repeat themselves. So, if the first Day of the Year falls on 1~I, then it won’t happen again for another 52 Years.
IMPLEMENTATION
It’s one thing to imagine a calendar system, however, implementing something this widespread has such a potential for disruption.
No worries. theAbysmal Calendar begins December 21st 2012 CE. This is the Winter Solstice which isn’t a weekday. The first Saturday of theAbysmal Calendar falls on Saturday December 22nd 2012 CE. As such, the first Year of theAbysmal Calendar will not require any adjustment of the Week.
theAbysmal New Year falls 10 Days earlier than the current one. This may cause some disruption, but when in doubt, declare a holiday.

There are 13 Constellations that provide a backdrop for the Sun’s journey through our skies (that’s according to the International Astronomer’s Union).
13 days to go with XX glyphs
13 weeks per quarter year
13 months of the 52~Week Calendar
13 lunar months in a long lunar year
13 Constellations
The constellation of Ophiuchus was reintroduced. He falls after Scorpio but before Sagittarius. This puts Libra in the centre with six signs on either side, making it a true balance once again.