calendar method(n = noun.act) calendar method of birth control, rhythm, rhythm method, rhythm method of birth control - natural family planning in which ovulation is assumed to occur 14 days before the onset of a period (the fertile period would be assumed to extend from day 10 through day 18 of her cycle);
is a kind of natural family planning

appointment calendar, basal body temperature method, basal body temperature method of family planning, bradley method, bradley method of childbirth, calendar, calendar day, calendar method of birth control, calendar month, calendar week, calendar year, cascade method, church calendar, contraceptive method, ecclesiastical calendar, eclectic method, experimental method, farmer's calendar, gram method, gram's method, greek calendar, gregorian calendar, gregorian calendar month, hebrew calendar, hindoo calendar, hindu calendar, hindu calendar month, islamic calendar, islamic calendar month, jewish calendar, jewish calendar month, julian calendar, lamaze method, lamaze method of childbirth, leboyer method, leboyer method of childbirth, lunar calendar, lunisolar calendar, maieutic method, method, method acting, method of accounting, method of choice, method of fluxions, method of least squares, mohammedan calendar, montessori method, moslem calendar, muhammadan calendar, muslim calendar, new style calendar, old style calendar, ovulation method, ovulation method of family planning, perpetual calendar, powder method, read method, read method of childbirth, relaxation method, revolutionary calendar, revolutionary calendar month, rhythm method, rhythm method of birth control, roman calendar, scientific method, sentence method, socratic method, solar calendar, statistical method, straight-line method, straight-line method of depreciation, teaching method, whole-word method, withdrawal method, word method