[[Ponies]], not having fingers on which to count, reckoned in prehistoric times according to a unary system of tally marks (i.e. one mark for each item counted), of various shapes. (Archaeologists have found marks made with hooves and horns in soft materials, the so-called ugulaform and corunaform inscriptions, besides painted marks and counting tokens. ) 

Over time, to make the tally marks easier to read, different numbers were arranged in different patterns, similar to the how the pips on a die can be counted, but can also be recognized by their arrangement without individually counting the pips. These came to be simplified into distinct figures, of which the number varies in different prehistoric equine cultures. Most of the lower-valued numerals are similar and retain a direct association between the number represented and the number of strokes in the figure.

With no particular natural base, the number of signs proliferated. At the same historical period, simple proto-writing had developed using symbols for concrete objects, and there was some borrowing of object-signs for numerical use as well.  When large numbers were reckoned, it was according to ad-hoc “unit” bases specific to categories of objects and chosen for practical reasons, similar to how we might request a “gross” or a “baker’s dozen” of something rather than specifying the base-10 number (144 or 13 respectively.) So, for example, an inscription might read:

{{{
    5 <small-fruit-baskets> 8 <apples>
    “258 apples.”
}}}

A basket being 50 apples, thus this refers to 258 apples. Reference to even larger numbers was by counting in a special base referring to score of other things, which was most commonly the largest familiar base, the “season.”

{{{
    2 <season> 7 <herd> 2 <pony>
     “238 ponies.” (2*90 + 7*8 + 2)
}}}

The “units” for days was also the “season” of ninety days, though the “month” of thirty days was used at the same time. A standard “herd” was eight ponies. Other competing systems reckoned units-of-units in compound units, e.g.

{{{
    3 <herd> of <herd> 5 <herd> 6 <pony>
    “238 ponies.” (3 * 8*8 + 5 * 8 + 6)
}}}

This was cumbersome for arithmetic but endured in many forms for centuries. According to later legend, the great [[Fillitas]] of [[Ponylonia]] reformed the system, creating a base-thirty positional number system, allegedly by multiplying the first four prime numbers. The zero and decimal point were, in any case, developed by the beginning of the [[pre-classical period]].

As the [[Cosmology|heavenly bodies still moved naturally at this time]], a calendar was developed based on an approximation of these motions. When the unicorns ended the horrors and bloodshed of the [[Intercalary Wars|Great Leap Year Wars]] of the late pre-classical period by taking over control of the motion of these objects with magic, they implemented a mathematically calculated idealized version of this calendar, ending the contentious requirement for intercalary months that had provoked such terrible conflict among ponykind.

The calendar of the [[classical period]] has thus come down unmodified until the present, though due to the actions of [[Nightmare Moon]] the movement of the [[sun]] and [[moon]] with respect to the [[constellations]] has changed somewhat from earlier times. (The limited precision of calculations made by the designers of the original calendar have also affected traditional ceremonial astronomy. In the Royal Age, proposals were considered to adjust the length of the day to bring the sun and moon back into synchronization with the stars as they were known by pre-classical astronomers.) The moon and sun are, necessarily, kept in synchronization with each other according to the calendar.


The annual (“seasonal” or “high royal”) [[Ponylon|Ponylonian]] [[Calendar]], as used in the present, consists of 360 days, broken down into 4 seasons, each of 3 months, each of 30 days.