A rhythm method of natural birth control.

The amount of time between the beginning of the first day of January and the end of the last day of December in the Gregorian calendar. (365 days, or 366 in a leap year)

The calendar currently used in the western world. It replaced the Julian calendar and was devised to halt the slow drift of the vernal equinox towards earlier in the year.

(religion, Jewish) The annual calendar used in Judaism. It determines the Jewish holidays, which Torah portions to read, yahrzeits (Yiddish: yortsaytn), and which set of Psalms should be read each day.

A calendar based on the movement of the Earth around the Sun, which defines the year. Dates indicate the position of the Earth during this revolution.

A calendar that measures the passage of the year according to the phases of the moon, as opposed to the revolution of the earth around the sun; a calendar of the lunar year.

The calendar which was used in the western world before the present-day Gregorian calendar. The Julian calendar differed in having all multiple-of-4 years as leap years.

(law) A hearing at which a judge will require all attorneys with cases pending before the court to appear so that the court may schedule hearings and trials.

A calendar used to count down the days of Advent, having windows revealing a hidden picture or gift on each day.

(finance) An options strategy or position involving the simultaneous purchase and sale of options of the same class and strike price but with different expiration dates.