HP Integrity NonStop J-Series - Manual (Page 64)

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©Copyright 1996 Rogue Wave Software
Chapter 4: Using Class RWDate
Example ❍
Constructors ❍
Class RWDate represents a date, stored as a Julian day number. Commonly used in software,
this compact representation allows rapid calendar calculations, shields you from details such as
leap years, and performs easy conversions to and from conventional calendar formats.
You don't need to know Julian day numbers to benefit from their use in Tools.h++. If you are
interested, the algorithm Tools.h++ uses to convert common calendar dates to Julian day
numbers is given in "Algorithm 199" from Communications of the ACM, Volume 6, No. 8,
Aug. 1963, p. 444.
The Gregorian calendar now used nearly world-wide was introduced by Pope Gregory XIII in
1582, and adopted in various places at various times. It was adopted by England on September
14, 1752, and thus came to the United States. We mention this because an
RWDate for a day
prior to the adoption of the Gregorian calendar is only valid in the sense that it is an
extrapolation back from the Gregorian system. Printing such an RWDate , or using its methods
to deal with specific day or month names, may have unexpected results.