The Andrastian Chantry calendar consists of 12, 30-day months - rounding the entire year up to 360 days. The majority of Thedas celebrates 5 major holidays, each tied to the transition of a season or, in the case of First Day, the beginning of a new year. The 5 main holidays, called annums
, take place at the beginning of the month within which they fall. Annum means "annually" or "yearly". Though not reflected on the calendar itself, some annums last longer than a single day with celebrations occasionally extending into a fortnight depending on region.
Although each month has a "high" name in the language of Ancient Tevinter, Thedosians commonly use the "low" names. Typically, only courts and scholars use the high names for months.
The Chantry calendar measures time in "Ages". The current one is the Dragon Age, while the period before was the Blessed Age. Each Age lasts approximately a century and there have been 9 so far: Ancient, Divine, Glory, Towers, Black, Exalted, Steel, Storm, Blessed, and Dragon. Typically, the Divine Age is recorded as the "First Age" with scholars relating the Ancient Age as being the period of history when chronicling events was not yet common practice.
Though we've based this calendar on the Chantry Calendar in the Dragon Age game, our calendar won't be 100% canon since, as we progress in-game, we'll be adding more holidays in the future. While some holidays do fall on the first of the month, not all newly implemented annums will have to meet this same standard.
We also haven't gone too in depth with documenting the whole of recorded, Chantry history here as it is very exhaustive. If you want to learn more about what happened in each "Age"—this external source will help fill in some blanks for you and there's also a detailed Timeline for the current, "Dragon Age".