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/* xbdate.h
XBase64 Software Library
Copyright (c) 1997,2003,2014,2022 Gary A Kunkel
The xb64 software library is covered under the terms of the GPL Version 3, 2007 license.
Email Contact:
XDB-devel@lists.sourceforge.net
XDB-users@lists.sourceforge.net
*/
#ifndef __XB_XBDATE_H__
#define __XB_XBDATE_H__
#ifdef CMAKE_COMPILER_IS_GNUCC
#pragma interface
#endif
namespace xb{
#define XB_FMT_WEEK 1
#define XB_FMT_MONTH 2
#define XB_FMT_YEAR 3
// next value is added to the date calculation to match dbase calculation
// first valid dbase date is 01/01/0001
#define JUL_OFFSET 1721425L
//! @brief xbDate class.
/*!
This xbDate class handles two type of date values:<br>
1) Gregorian dates with a format of CCYYMMDD. This is how dates are stored in dbf files.<br>
2) Julian dates calculated as the number of days since 1901-01-01 + 1721425.<br>
Leap Years: The routines in the class support both leap years (one every four
years) and leap centuries (one every four hundred years.)
A leap year is a year having 366 days, which can be evenly
divisible by 4 and not by 100.<br>
Leap centuries are years which are evenly divisible by 400.<br>
From a programming perspective, Julian dates are useful for date
arithmetic, determining the difference between two dates or calculating
a future or past date.<br>
To determine the difference between two dates, convert both dates to a
Julian date and subtract one from the other.<br>
To calculate a future or past date, convert the base date to a Julian date,
add (or subtract) the number of days necessary to (from) it and convert the
julian date back to a Gregorian date.
*/
class XBDLLEXPORT xbDate : public xbSsv {
public:
xbDate();
xbDate( const char * Date8 );
xbDate( const xbString &Date8 );
xbDate( xbInt32 lJulDate );
xbDate( xbUInt16 iInit ); // Constructor used to set the static variables, also defaults to sysdate
~xbDate();
void operator=( const xbDate &d );
void operator+=( xbInt32 i );
void operator-=( xbInt32 i );
void operator++( xbInt32 i );
void operator--( xbInt32 i );
xbInt32 operator-( const xbDate & ) const;
const char * operator-( xbInt32 i );
const char * operator+( xbInt32 i );
xbBool operator==( const xbDate & ) const;
xbBool operator!=( const xbDate & ) const;
xbBool operator< ( const xbDate & ) const;
xbBool operator> ( const xbDate & ) const;
xbBool operator<=( const xbDate & ) const;
xbBool operator>=( const xbDate & ) const;
xbInt16 CalcRollingCenturyForYear( xbInt16 year ) const;
xbInt16 CenturyOf() const;
xbInt16 CharDayOf( xbString &sOutCharDay );
xbInt16 CharMonthOf( xbString &sOutCharMonth );
xbBool DateIsValid ( const xbString &sDate8 ) const;
xbInt16 DayOf( xbInt16 iFormat ) const;
xbInt16 CTOD( const xbString &sCtodInDate );
xbInt16 FormatDate( const xbString &sFmtIn, xbString &sFmtOut );
const char *Str() const;
xbBool IsLeapYear( xbInt16 iYear ) const;
xbBool IsLeapYear() const;
xbBool IsNull() const;
xbInt32 JulianDays() const;
xbInt16 JulToDate8( xbInt32 lJulDate );
xbInt16 LastDayOfMonth();
xbInt16 MonthOf() const;
xbInt16 Set( const xbString &Date8 );
xbInt16 Sysdate();
xbInt16 YearOf() const;
#ifdef XB_DEBUG_SUPPORT
void Dump( const char * title );
void DumpDateTables();
#endif
private:
void SetDateTables();
xbString sDate8; // CCYYMMDD date format ie; 20140718
// Null date is identified by sDate.Len() < 8
static int iAggregatedDaysInMonths[2][13];
static int iDaysInMonths[2][13];
};
} /* namespace */
#endif /*__XB_XBDATE_H__ */
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