Period Class
A Period defines the time intervals, days or months that should be included or excluded in a schedule. It is composed of 4 distinct period components: MinutesInDay, DaysInWeek, DaysInMonth and MonthsInYear. A Period object is in-schedule only if all of its 4 components are in-schedule. Otherwise, it is out-of-schedule.
MinutesInDay contains a set of 1440 continuous 1-minute intervals in a day. The MinutesInDay object is in-schedule if the time for checking the schedule is included in the MinutesInDay.
DaysInWeek contains a set of 7 days in a week. A DaysInWeek is in-schedule if the day of date for checking the schedule is included in the DaysInWeek.
DaysInMonth contains a set of 31 days in a month. A DaysInMonth is in-schedule if the day in the date for checking the schedule is included in the DaysInMonth.
MonthsInYear contains a set of 12 months in a year. A MonthsInYear is in-schedule if the month of the date used for checking the schedule is included in the MonthsInYear.