The calendar year for the people of the Isles consists of thirteen months of 28 days each, in total 364 days, as well as an indeterminate period which follows it, named the Fugue Feast. A new year only begins once the astronomical clock is officially reset by the High Overseer of the Abbey of the Everyman.
The months of the year in the franchise are as follows:
- The Month of Earth
- The Month of Harvest
- The Month of Nets
- The Month of Rain
- The Month of Wind
- The Month of Darkness
- The Month of High Cold
- The Month of Ice
- The Month of Hearths
- The Month of Seeds
- The Month of Timber
- The Month of Clans
- The Month of Songs
- According to developer Harvey Smith, Dishonored was released with an error in the calendar. In the final version, the Month of Seeds and the Month of Harvest were inadvertently transposed. The calendar was later corrected in the Dishonored art book Dishonored: The Dunwall Archives and other media after that.
- A poster advertising an event on "Saturday" at the Preston Club suggests that the Isles use the same days of the week as the Earth common calendar. However according to Harvey Smith, "[W]e wanted to avoid the calendar we use because it is based on historic earth mythology", giving "(Thor/Thursday)" as an example.
- There are at least three known seasons that correspond with real world seasons. The season of winter encompasses the Months of Darkness, High Cold and Ice.  The Month of Harvest falls within the Empire's summer, and the Month of Wind within its fall.
- A pre-release poster for the Greaves Lightning Oil company uses the month of August on its chart, instead of using this calendar.
- The majority of Dishonored is set in between the Months of High Cold and Hearths, 1837.
- A calendar of 1849 can be found in Stilton Manor in Dishonored 2. It is the souvenir for the mission A Crack in the Slab.