{	GETDATE with no range limits

	This inputs a date in the format number-char-number-char-number
	(ie: 1-22-80 or 10/5/77) and returns an integer in the range
	1..maxint. Yrbase sets the initial year which will be accepted,
	and yrspan determines the last year. Yrspan cannot exceed 89,
	in order to remain within range.

	Note that the prompt must be passed to MAKEDATE from the calling
	program.

	This package requires global declarations
		TYPE	string255 = string 255;
			byte = 0..255;

	The following additional procedure must be declared;
		PROCEDURE prompt;
}

PROCEDURE getdate (msg : string255; VAR mo, da, yr : byte);

CONST	yrspan = 89;
	yrbase = 10;

VAR	ch : char;
	good : boolean;
	temp : integer;

begin
  	repeat
		good := true;
		prompt (msg);
		readln (mo,ch,da,ch,temp);
		temp := temp mod 100 - yrbase;
		if (da < 1) or (da > 31) or (mo < 1) or (mo >12)
			or (temp < 0) or (temp > yrspan) then
			begin
				good := false;
				writeln (' *** Bad date ***')
			end
	until good;
	yr := temp
end;

FUNCTION makedate (msg : string255) : integer;

CONST	yrbase = 10;

VAR	days : integer;
	da, mo, yr : byte;
	str : string255;

begin
	getdate (msg,mo,da,yr);
	case mo of
		1 : days := 0;
		2 : days := 31;
		3 : days := 59;
		4 : days := 90;
		5 : days := 120;
		6 : days := 151;
		7 : days := 181;
		8 : days := 212;
		9 : days := 243;
		10 : days := 273;
		11 : days := 304;
		12 : days := 334;
		end;
	days := days + (yr*365) + (yr div 4) + da;
	if ((yr + yrbase) mod 4 = 0) and (mo > 2) then days := days + 1;
	makedate := days
end;