# Section 8.7:
Date & Time Classes

This section of the required library contains definitions of those abstractions and classes which provide date and time related services.

1. Abstract Classes

   1. $DATES - this abstraction models the concept of a calendar date - which may not necessarily conform to the Gregorian calendar (for example in Japan).

2. Immutable Classes

   1. WEEKDAYS - this enumeration class implements the days of the week.
   2. DAY_SET - this class implements the concept of a set of days (eg for work or for the weekend).
   3. MONTHS - this enumeration class implements the months in a year.
   4. MONTH_SET - this class implements the concept of a set of months (for example, for a season such as Winter).
   5. TIME_STAMP - this class implements the concept of a time stamp which includes both date and time-of-day.
   6. DATES - this class implements the manipulations which are appropriate to a date without any associated time of day.
   7. TIMES - this class implements the manipulations which are appropriate to a time of day value.
   8. ELAPSED - this class implements the concept of a time period or 'elapsed' time which can never be negative.

3. Reference Classes

   1. TIMER - this class implements the concept of an activity timer based upon any timer provided by the underlying execution environment.

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Comments or enquiries should be made to Keith Hopper. Page last modified: Friday, 10 March 2000. |