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Diffstat (limited to 'src/include/xbdate.h')
| -rwxr-xr-x | src/include/xbdate.h | 125 |
1 files changed, 125 insertions, 0 deletions
diff --git a/src/include/xbdate.h b/src/include/xbdate.h new file mode 100755 index 0000000..e914d65 --- /dev/null +++ b/src/include/xbdate.h @@ -0,0 +1,125 @@ +/* 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__ */ + |