The Ritual Calendar

The year is divided into 12 months, each 28 days long. This brings the calendar year to a length of 336 days.
The Ritual Calendar has been widely adapted in the world of Samra. It records the most notable religious festivals.
The solar year is several days shorter than the calendar year, but on the eve of the new year, the sun briefly speeds up to catch up with Samra and its moons. Nobody knows for sure why this happens, but most educated guesses point towards whims of the Sun God, Amaunator.