Sendris E'vana Calendar

Senris E'vana uses the calendar system of The Forgotten Realms.
A year consists of 365 days. In the E'vana Calendar, the year is divided into twelve months of thirty days, loosely following the synodic cycle of the moon. A month is made up of three tendays. Five annual holidays, falling between the months, complete the 365-day calendar. Once every four years, the Morrith Calendar includes Shieldmeet as a "leap day" following Midsummer. Individual days of a tenday have no special names. Instead, they are denoted by counting from the beginning of the period ("first day," "second day," and so on). Days of the month are designated by a number and the month name. For example, sages would record an event as occurring on "1 Mirtul" or "27 Uktar." People might also refer to a given day by its relationship to the current date ("two tendays from today") or the nearest holiday ("three days past Greengrass").
The pictures below come from this PDF, created by Natural20_UK of D&D Beyond.