Standardized Tridecimal Lunisolar Calendar[]
(a standardized version of the Lunar Aymara calendar with some elements from the "theAbysmal calendar", both being "13*28" calendars aligned with the solstices)
This is a calendar that is divided in a 13-28 way, that is, 364 of the 365 days are divided in 13 months, each with exactly 28 days, with the remaining day serving as New Year Day. (unlike many 13-28 calendars, this doesn't disrupt the weekday cycle, it still counts as a day of the week) It is designed so that the monthless New Year Day (or "Day Zero") falls in the Southern Winter Solstice (usually in 21st of June, as in the shown examples); and that the Leap Day is inserted in the middle of the year, falling in the Southern Summer Solstice (usually in 21st of December, as in the lower table). Leap years, however, because of astronomy, are not always necessarily every 4 years. The graphic notation is compact and easy to understand. Color indicates month, the upper edge indicates which quarter of the month, and the number of dots indicate the day of the month quarter. (the day of each month quarter does not necessarily always correspond to a specific day of the 7-day week cycle, because, again, neither the aforementioned Day Zero nor the Leap Day in the middle of the year disrupt the weekday cycle.) A special symbolis used to represent the solstices, whether it's the monthless Day Zero or the December Solstice Leap Day. The calendar graphs are also straight-forward: each "quarter-month" is numbered from 01 to 52 with golden numbers, and the divisions between the 12 Gregorian months are marked with turquoise lines except the December-January division, indicating a new Gregorian year, in which the line is golden (It is easy to know which Gregorian month is which, as the Tridecimal Month IX perfectly aligns with Gregorian February if it's a non-leap year in both calendars and Day Zero is in 21st of June). The calendar is also organized in four columns, which correspond to the four traditional seasons, from left to right: winter, spring, summer and autumn in the southern hemisphere (or summer, autumn, winter and spring in the northern hemisphere) This calendar and the Aymara calendar have a 5000 year difference. This calendar started in 21st of June, 1492, Proleptic Gregorian (which is equivalent to 12th of June, 1492 in the Julian calendar, the calendar used back then), while the Aymara calendar adds 5000 to the year number. For anyone curious, the subdivisions of the days are not hours, minutes or seconds, but instead into thousandths, and there are no timezones either: instead, 000 indicates midnight in 72 degrees west (or 80 gradians west, to remain consistent with the decimal-centred units)