INFORMIX-ESQL/C Programmer's Manual ESQL/C Function Library

The rdayofweek() function returns the day of the week as an integer value for an internal DATE.

mint rdayofweek(jdate)

	int4 jdate;

 



jdate  

is the internal representation of the date. 

The demo directory contains this sample program in the rdayofweek.ec file.

/*
* rdayofweek.ec *

The following program accepts a date entered from the console.
*/

#include <stdio.h>

main()
{
mint errnum;
int4 i_date;
char *day_name;
char date[20];
int x;

static char fmtstr[9] = "mmddyyyy";

printf("RDAYOFWEEK Sample ESQL Program running.\n\n");

/* Allow user to enter a date */
printf("Enter a date as a single string, month.day.year\n");
gets(date);

printf("\nThe date string is %s.\n", date);

/* Put entered date in internal format */
if (x = rdefmtdate(&i_date, fmtstr, date))
printf("Error %d on rdefmtdate conversion\n", x);
else
{
/* Figure out what day of the week i_date is */
switch (rdayofweek(i_date))
{
case 0: day_name = "Sunday";
break;
case 1: day_name = "Monday";
break;
case 2: day_name = "Tuesday";
break;
case 3: day_name = "Wednesday";
break;
case 4: day_name = "Thursday";
break;
case 5: day_name = "Friday";
break;
case 6: day_name = "Saturday";
break;
}
printf("This date is a %s.\n", day_name);
}

printf("\nRDAYOFWEEK Sample Program over.\n\n");
}

RDAYOFWEEK Sample ESQL Program running.

Enter a date as a single string, month.day.year
10.12.96

The date string is 10.12.96.
This date is a Saturday.

RDAYOFWEEK Sample Program over.