The Dove Calendar is a simple calendar, devised by Karl Palmen, where the days are grouped into consecutive periods of seventeen days called doves.

Years alternate between 21 and 22 doves (357 and 374 days) for 33 years beginning and ending with a short year of 21 doves. This gives rise to a mean year of 365.242424.. days.

See The Dove Calendar for more details.