JAVASCRIPT - Día de la semana a partir de una fecha

Día a partir de una fecha

Compatibilidad: Ms Internet Explorer, Netscape
Este script permite averiguar el día de la semana de una fecha expresada del siguiente modo: 7.6.73

[ Muestra el ejemplo práctico ]

el código para insertar en tu página

<TITLE>Ejemplos Javascript: ejemplo práctico </TITLE>

<SCRIPT LANGUAGE="LiveScript">
<!--
//Author:  Jason Anguiano
//Date:    February 25, 1996
//Email:   jangui@csn.net
//Program: What day of the Week? Written in JavaScript

/* This JavaScript can be re-used or modified, if credit is given in the source code. 
Thank you. I cannot be held responsible for any unwanted effects due to the    
usage of this JavaScript or any derivative.  No warrantees for usability    
for any specific application are given or implied.      
Sorry about that, ...now where were we?*/

function mod(x, x_div){    
	for (var i=x; i>=x_div; i -= x_div);    
		return i;
}

function pushbutton(form){     
	//Check for a valid date			     
	if ((checkNum(form.day.value,1,31)) && (checkNum(form.month.value,1,12)) && (checkNum(form.year.value,0,99))){
		var cur_day = parseInt(form.day.value,10);	
		var cur_month = parseInt(form.month.value,10);	
		var cur_year = parseInt(form.year.value,10);	
	//alert(" "+cur_day+" "+cur_month+" "+cur_year);	
	//Significant value	
	var sig_val;	
	if (cur_month == 1)		
		sig_val = 0;	
	else if (cur_month == 2)		
		sig_val = 3;	
	else if (cur_month == 3)		
		sig_val = 3;	
	else if (cur_month == 4)		
		sig_val = 6;	
	else if (cur_month == 5)		
		sig_val = 1;	
	else if (cur_month == 6)		
		sig_val = 4;	
	else if (cur_month == 7)		
		sig_val = 6;	
	else if (cur_month == 8)		
		sig_val = 2;	
	else if (cur_month == 9)		
		sig_val = 5;	
	else if (cur_month == 10)		
		sig_val = 0;	
	else if (cur_month == 11)		
		sig_val = 3;	
	else if (cur_month == 12)		
		sig_val = 5;		
		var val1 = mod((cur_year + parseInt(cur_year/4) + cur_day + sig_val),7);		
	
	//Display the correct file        
		if (val1 == 0)		
			alert("Sunday");
        	else if (val1 == 1)		
			alert("Monday");
		else if (val1 == 2)		
			alert("Tuesday");
		else if (val1 == 3)		
			alert("Wednesday");
		else if (val1 == 4)		
			alert("Thursday");
		else if (val1 == 5)		
			alert("Friday");
		else if (val1 == 6)		
			alert("Saturday");
			return true;     
		}     
		else	
		return false;
}
//-->
</SCRIPT>

</HEAD>

<FORM NAME = "What_Day">
<PRE><B>Day:</B>   
<INPUT TYPE="num" name="day" onChange="if (!checkNum(this.value, 1, 31)){this.focus();this.select();} else {}" size=10 value="">	
<B>Month:</B> 
<INPUT TYPE="num" name="month" onChange="if (!checkNum(this.value, 1, 12)){this.focus();this.select();} else {}" size=10 value="">
<B>Year:</B>  
<INPUT TYPE="num" name="year" onChange="if (!checkNum(this.value, 0, 99)){this.focus();this.select();} else {}" size=10 value=""> 	 
<INPUT TYPE="button" name="Find_Out" value="OK, I'm ready" onclick="pushbutton(this.form)"></PRE>
</FORM>

</body>
</html>