This class is inherited from the TPresent
class. An instance of this class is used by the programmer to set, access,
add to, subtract from, and otherwise maintain dates. This class uses a
four-byte date storage method known as CYMD, where the date is stored in four
parts, one byte each, consisting of the century, the year in the century, the
month, and the day. For example, May 19, 2003 would be stored in four
bytes with the values 20, 3, 5, and 19. This class also uses an "absolute
Julian" date, which is the number of days since the first day of A.D. In
other words, January 1, 0001 A.D. is day one and May 19, 2003 is day
731719. The public member functions are as follows:
- TDate::TDate()
- This is the default constructor. It sets the internal date to the
current date.
- TDate::TDate(CTime Date)
TDate(char*CYMD)
TDate(int Century, int Year, int Month, int Day)
- These constructors set the internal date to the specified date.
- long TDate::GetDate()
long TDate::GetDate(char*CYMD)
long TDate::GetDate(char*Century, char*Year, char*Month, char*Day)
long TDate::GetDate(CString&Text)
long TDate::GetDate(CTime&Text)
int TDate::GetYear()
int TDate::GetMonth()
int TDate::GetDay()
- These member functions return the internal date in the format
requested. The
CString
format is mm/dd/yyyy. The TDate::GetDate() functions also
return TDate::ThisJulian.
- char LeapYear()
static char LeapYear(short*Year)
- These member functions return a one if the internal or specified year is a
leap year, and a zero if not. The result of these functions may be added
or subtracted from Julian dates if they are after February 28th.
- long TDate::SetDate()
long TDate::SetDate(TDate Date)
long TDate::SetDate(CTime Date)
long TDate::SetDate(char*CYMD)
long TDate::SetDate(CString Date)
long TDate::SetDate(int Century, int Year, int Month, int Day)
long TDate::SetDate(long Julian)
TDate& TDate::operator=(TDate Date)
TDate& TDate::operator=(CTime Date)
- These member functions set the internal date from the format
specified. The version with no arguments set the internal date to the
current date. The
CString
format must be specified as mm/dd/yyyy with leading zeros optionally
suppressed. If a two-digit year is entered, the function will attempt to
add the most logical century. It is wise to always specify a four-digit
year. The TDate::SetDate() functions also return
TDate::ThisJulian after it has been set.
- long TDate::AddDate(char*CYMD)
long TDate::AddDate(TDate Date)
long TDate::AddDate(int Century, int Year, int Month, int Day)
TDate& TDate::operator+(TDate Date)
long TDate::SubtractDate(char*CYMD)
long TDate::SubtractDate(TDate Date)
long TDate::SubtractDate(int Century, int Year, int Month, int Day)
TDate& TDate::operator-(TDate Date)
- These member functions adjust the internal date with the date
specified. The TDate::AddDate() and
TDate::SubtractDate() functions also return TDate::ThisJulian after
it has been set.
- BOOL TDate::operator==(TDate& Date)
BOOL TDate::operator!=(TDate& Date)
BOOL TDate::operator>(TDate& Date)
BOOL TDate::operator<(TDate& Date)
BOOL TDate::operator>=(TDate& Date)
BOOL TDate::operator<=(TDate& Date)
- These member functions compare the internal date with the date
specified. They return TRUE or FALSE based on the success or failure of
the requested comparison.
- long TDate::ThisJulian
- This data member may be inherited. It contains the "absolute Julian"
date. It is returned as the value of most member functions in addition to
their other operations.
- int TDate::Year
- This data member may be inherited. It is used for calculations which
require the four-digit year.
- union ThisDateDef {int i; char p[4];} ThisDate
- This member structure may be inherited. It stores the internal date in
CYMD format. ThisDate.i may be compared with that of another
TDate class as a four-byte integer. The four ThisDate.p
variables contain the day, month, two-digit year, and century
respectively.
