Calendars are the structure by which civilizations keep track of events and the time between them. While it is common for early civilizations to develop their own, more developed civilizations tend to standardized calendars between themselves to ease diplomatic negotiations and trade. These calendars tend to dominate a region of trade, but do not necessarily reach global standardization until very late in an era, meaning that there will often be several different calendars in use across the planet.
The Yasarian Calendar was proposed in 1560 SE by Yasar Lightfoot. It remains the most popular calendar in Niera, owing to its adoption by several of the most dominant empires throughout the years since. It breaks the year (412 days) up into 9 months with an additional period of 4 days at the end, known as the "Erenium".