Duration
AnnualDecennialTwo yearlyThree yearlyFour yearlyFive yearlyThree times a yearFour times a yearDaily – business weekDailyTwice-a-dayHourlyBihourlyTrihourlyIrregularlyMonthlyYearlyTwicemonthlyThree monthlyTwice a monthThree times a monthMinutelyOccasional annualOccasional monthlyQuarterlyTwice yearlyWeeklyTwo-weeklyTriweeklyFour-weeklyTwice-a-weekThree times a weekContinuousDiscontinuedOnce onlySchool yearStudy yearTemporarily halted