After the incident at Yalat Oasis and the subsequent fortification of Tartarus Hold, the Emperor declared a period of peace and consolidation. He restructured the calendar in the year 850 ATC to the Age of Prosperity, referring to it as the year 0ap. Scholars outside of the Emperors influence called it the Second Age, or 2e for short. One thing they agreed upon, however, was the calendar itself. Due to Arcaniums chaotic effects on the weather, scholars agreed that the calendar based on the seasons was no longer valid. In fact, the weather was so changed by the Arcanium that the seasons in Feredas are random, changing (sometimes staying the same) after every Manastorm. The effects of these Manastorms seem to be beneficial for farmers, as crops grow much faster, usually allowing harvest just before the next storm. Occasionally, farmers will emerge from their storm shelter to find their crops fully grown, despite being planted only days prior. As a consequence of this unreliability, food may be plentiful but it is very inconsistent as to WHICH foods are available.
Sarella's calendar year is 333 days, broken up into equivalent months with a small break between each year. Each month is 22 days long, based on the cycle of the moon Olympia (for Ragoth) and the cycle of Manastorms (for Feredas). There are 3 seven-day weeks, with the last day of the month acting as a Storm Day, with a Manastorm crashing across the continent of Feredas heralding a change in season. There are 15 of these months in a calendar year, with the last month followed by the Stormfury, a 3-day long period with Manastorms occurring frequently.
YEAR:
Years are now referred to with an Era designation, such as 120 2e for the 120th year of the second Era. The Empire refers to it as the Age of Prosperity, or AP. Prior to this, the years were referred to as ATC, or After The Cataclysm, an ancient cycle of destruction stopped centuries ago.
MONTHS:
Each month is numbered, with the Imperial calendar's names being standard. Each is named for one of Gallus' 15 Virtues, and is expected to be observed more closely that month.
DAYS:
The days in Feredas are named for significant pieces of its' past.
Fedas - Feredas Day (simply named after the continent)
Aatildas - Aatildan's Day (named for an ancient Paladin, widely regarded as the ideal all Paladins should strive towards)
Doma - Dominion Day (named for the unification of Harithma under the old King Gaius)
Yundas - Day of the Young (most races are referred to as the Young Races by texts found in Precursor sites)
Galla - Gallus Day (named for Emperor Gallus, the immortal unifier of all Feredas and current head of Imperial government)
Harda - Harmony Day (named for the sacrifice of an ancient hero, leading to the cycle of Destruction finally ending)
Endas - End Day (traditionally the end of the week, the day of rest)
MOONS:
Olympia - Said to be the moon of the gods, this moon has a longer 22-day cycle, and is thought to embody patience and discretion.
Infernia - Said to be the moon of devils, demons, and all evil things, this moon has a shorter 16-day cycle and is thought to embody brashness, selfishness, and short-term thinking.
Outerworld - Permanently locked to Sarella and stuck in its' shadow, this small, lightless moon was unknown until relatively recently, possibly due to the planet being in a permanent state of darkness. After recent discoveries, scholars now mostly agree that Arcanium originated from Outerworld.