Calendars

A week of seven days is natural if one divides a lunar month of twenty-eight days into quarters. That is almost certainly the reason we use seven. The weeks can start on recognizable phases of the moon, new, quarter, full. Of course, a twenty-eight day month does not mesh that well with a twelve month, 365 day year, so most calendars end up being something of a mess of compromises and contradictions.

Twelve months, to be sure, are a tidy way of dividing the year. If each were equal, mostly likely at thirty days, there are only five days left over. Those can be addressed in various ways, as outside the normal sequence of days and weeks. A thirteen month year has its own advantages and disadvantages; it does not line up with the solstices and equinoxes in the same manner as twelve months.

That may or may not be bothersome to a society. If we do use a thirty day month, the weeks needn’t be of seven days. Ten or five might do as well, or six, for that matter. Or, as long as we are not tying the months to the moon, they might be of some other length altogether. Forty-five, for example—half of a season. That could be divided neatly into weeks of five or nine days.

All these are things to be considered in world-building. They do assume a world with the same length of year and phases of the moon as our own; both fantasy and science fiction may have to deal with worlds with completely different rules. The Exura where most of my fantasy fiction is set does not present this difficulty, but I do keep in mind that other worlds are not necessarily the same.

I have given my Mura the thirteen month calendar. Yes, with seven day weeks. They do not line up at all with the seasons, though the solstices and equinoxes do always end up on the same date. Only one day is not named as a normal day, belonging to neither a week nor a month, and that is the New Year Day, celebrated at the spring equinox. On leap years, an extra day is inserted just before it. These are the names of the months, as use in the Muram Empire:

the Month of the Ram — March 21 to April 17
the Month of the Fox — April 18 to May 15
the Month of the Bull — May 16 to June 12
the Month of the Rooster — June 13 to July 10
the Month of the Grasshopper — July 11 to August 7
the Month of the Lion — August 8 to September 4
the Month of the Fish — September 5 to October 2
the Month of the Hawk — October 3 to October 30
the Month of the Horse — October 31 to November 27
the Month of the Wolf — Novemeber 28 to December 25
the Month of the Crow — December 26 to January 22
the Month of the Rabbit — January 23 to February 19
the Month of the Frog — February 20 to March 19

New Year Day — March 20

Most of the old Muram kingdoms across the Greater Sea from the Empire utilize some variant of this calendar, although the names of the months may differ. It was never adopted, however, by the Sharshites or other nationalities ruled by the Mura at some point. We can take a look at some of their calendars another time.