## Summary

- Fixed Quarters is a non-perpetual solar calendar.
- Its year begins approximately with the spring equinox in the northern hemisphere and the autumn equinox in the southern hemisphere.
- The year is divided in 4 quarters of 91 days each.
- Each quarter is divided in 3 months of 30, 30 and 31 days respectively.
- At the end of last month of fourth quarter, is added the day 365, enumerated 32.
- In leap years, also is added the day 366, enumerated 32 too, resulting a double day of 48 hours.
- Within the year, the quarters are identical except by days 32, added to the last quarter.
- The enumeration of years is done according to the system Human Era or Holocene Era proposed by Cesare Emiliani.
- The week have 7 days.

## Cycles

Fixed Quarters is a solar calendar, meaning its bigger cycle corresponds with rotation of the Earth around the Sun.

It is non-perpetual, meaning the day of the week in which fixed quarters year begins change every year.

This implies in successive years the arrangement of dates on the days of the week is different. Celebrations, holidays and birthdays vary their position in the week with the passing of years.

In Fixed Quarters calendar the 7 days week is kept.

The days of the week are enumerated from 1 to 7, where 1 corresponds to Monday in the present denomination. Until now they are named D1…D7.

Fixed quarters year begins approximately with the spring equinox in the northern hemisphere and the autumn equinox in the southern hemisphere.

The fixed quarters year is divided in 4 quarters of 91 days each. Each quarter is divided in 3 months of 30, 30 and 31 days respectively. At the end of the last month of the fourth quarter, is added the day 365, enumerated 32.

In leap years, also is added the day 366, enumerated 32 too, resulting a double day of 48 hours.

Within the year, quarters are identical except by days 32, added to the last quarter. The quarters are of 91 days. As 91 is a multiple of 7, the 4 quarters begins on the same day of the week, that is, the quarters are corresponding. Therefore, the arrangement of dates on the days of the week is identical in the 4 quarters of the year. From this, comes the name Fixed Quarters.

Also because of the above, in the Fixed Quarters calendar corresponding months are identical except for the addition of extra days in the month 12.

Months are enumerated from 1 to 12. Until now they are named M1…M12.

In Fixed Quarters calendar are corresponding months:

- M1, M4, M7 and M10.
- M2, M5, M8 and M11.
- M3, M6, M9 and M12.

## Representation

Thanks to this symmetry, the Fixed Quarters calendar can be represented in full or annual form and reduced or quarterly form.

**Full form**: Are represented the 4 quarters, equivalent to represent the 12 months.

**Reduced form**: Are represented a quarter and the extra day 32.

Example: Fixed quarters year starting on D1.

## Enumeration of years

The enumeration of years in Fixed Quarters is done according to the system Human Era or Holocene Era, created by Cesare Emiliani in 1993. Its name is derived from the Holocene geological age. Year 1 corresponds to year 10000 B.C. of Gregorian calendar.

It can’t be determined exactly when the Holocene geological age started, neither when must be considered the beginning of human civilization, but this period of just over 12 000 years, includes all recorded human history, until now.

The conversion is done by adding 10 000 to Gregorian year if it is A.D. and subtracting Gregorian year from 10 001 if it is B.C.

Anno Domini | Conversion | Human Era | |

Year zero | 10001 B.C. | 10001-10001 | 0 H.E. |

Year one | 10000 B.C. | 10001-10000 | 1 H.E. |

Last year B.C. | 1 B.C. | 10001-1 | 10000 H.E. |

First year A.D. | 1 A.D. | 10000+1 | 10001 H.E. |

Present year | 2017 A.D. | 10000+2017 | 12017 H.E. |

## Advantages

- Length of months is regular and easy to memorize. 30, 30, 31, 30, 30, 31, 30, 30, 31, 30, 30 and 32. Or simply 30, 30 and 31 (+1).
- Length of quarters is regular. 91, 91, 91 y 92. Or 91 (+1).
- Cycle of the 7 days week is kept.
- Displacement of dates on the day of the week is kept. But by adding the extra double day at the end of year the double displacement on the days of the week will be the same for all days in the following year.
- There is no a date for the leap day. Enumerate both extra days 32, eliminates the leap day date and therefore the problem of those born in the leap day. In common years the day 32 is simple and in leap years is a double day named by only one date, 32 of month 12. Those born in any moment of this double day will be registered the 32 of month 12.
- It’s easy to know what day of the week will be a given date.
- It can be represented in annual and quarterly forms.
- In the system Human Era all years are positive, which provides better historical perspective and continuity. This enumerating system is global and independent of religions and politics.

## Examples

Fixed quarters year 12014 is a common year, therefore only an extra day is added at the end of the fourth quarter.

Fixed quarters year 12016 is a leap year, therefore an extra double day is added at the end of the fourth quarter.