Date Serials

A floating point number representing a date and time

Description
	A date serial is a number that holds a date and time value in the same 
	format used by PDS or VBDOS. The value is a count of the days from 0:00 
	AM of December 30,1899; it's mainly used for easy counting of the time 
	between two dates.

	The date serial unit is one day and the fractional part represents the 
	time of the day. If a date serial is written into an integer, the time 
	is lost. FreeBASIC date serials are not limited to dates between 1753 
	and 2078 as in VBDOS. FreeBASIC date serial handling functions use KeyPgDoubleDouble
	arguments.

	FreeBASIC date serial handling functions require the inclusion of 
	vbcompat.bi or datetime.bi in the source.

	A date serial can be created by the functions KeyPgNowNow, KeyPgTimeserialTimeSerial+KeyPgDateSerialDateSerial
	, or KeyPgDateValueDateValue+KeyPgTimeValueTimeValue.

	The functions KeyPgYearYear, KeyPgMonthMonth, KeyPgWeekdayWeekday, KeyPgDayDay, KeyPgHourHour, KeyPgMinuteMinute, KeyPgSecondSecond allow to 
	recover the different components of a date serial.

	The KeyPgFormatFormat function has formatting expressions to print date serials in 
	a human readable way.

Example
	#include "vbcompat.bi"
	Dim a As Double, b As Double

	a = 0
	Print "The origin of the date serials is:"
	Print Format(a, "yyyy/mm/dd hh:mm:ss")
	Print

	a = Now
	Print "The time now is: "
	Print Format(a, "yyyy/mm/dd hh:mm:ss")
	Print

	b = DateSerial(2000,1,1)
	Print Int(a-b) & " days have passed since 2000/01/01"

   
