/*                     *** weekday.c ***                             */
/*                                                                   */
/* IBM - PC microsoft "C"                                            */
/*                                                                   */
/* function to determine the day of the week a given gregorian date  */
/* falls on.  Returns a 0 if successful or a -1 if not.              */
/*                                                                   */
/* WARNING - day must be declared to be at least 10 characters or a  */
/*           memory overwrite will occure.                           */
/*                                                                   */
/* Written by L. Cuthbertson, March 1983                             */
/*                                                                   */
/* Rewritten at August 1986 by Petri Helenius,			     */
/* 			       Sysop of Electric Empire              */
/*                             (+358-0-874 5258)                     */
/*********************************************************************/
/*                                                                   */

int weekday(indate,day)
char indate[],day[];
{
	static *char days [7][10] = {	"Sunday",
					"Monday",
					"Tuesday",
					"Wednesday",
					"Thursday",
					"Friday",
					"Saturday" };
	int iday;
	long julian,gtoj();

	/* get julian date */
	if ((julian = gtoj(indate)) == (-1)) return(-1);

	/* calculate day of week */
	iday = (julian-1) % 7;

	/* move weekday into character string */
	strcpy(day,days[iday]);

	/* done */
	return(0);
}